*Feel free to discuss amongst yourselves..Issac's video was flawed since he used a mat below mortar bed which gave a false result..., I have stated my opinion on this subject many more times than I care to, I have done a demo and stated my opinion again on all the aspects of a pre slope, it's a dead horse now and I won't entertain any questions or debate the subject here*
Well, what you DONT do, is apply caulk while screwing the cap on in between, which is what I did. Ow I can’t sleep thinking that there’s a shower I built, just waiting to fail.
Every shower I tear out with no preslope, smells terrible, which is caused by bacteria, this is my main complaint. At end of day, if water isn't leaving the pan and destroying everything, you are good(ish)
I agree that the issue is not that the dry pack itself clogs the weep holes. However, isn't it possible that over time, with the addition of detergent residue, mineral deposits and perhaps mold, the mortar (in the weep holes) eventually becomes less permeable or impermeable?
I love tile drama lol! All of you main guys putting out videos are awesome! I applaud you all. Being a contractor myself I don’t have the nerve to do videos so my hat is off to y’all!
Capillary action is stronger than gravity, but when complete saturation of water in mortar occurs at some point, it would seem helpful to have a slope to aid in drainage purposes.
Everyone agrees that preslope helps. what he is trying to show you is that water will pull itself out of the drypack and into the drain without preslope. Preslope is only a requiment when you are on a concrete basement floor and the floor slopes away from the drain. In this scenario in his video, the base is perfectly flat and then the liner goes up the sides so it's like a preslope of 0 which in theory will drain. But when you have the slope of the base going away from the drain now you are relying more and more on the wicking effect to pull the water up the slope and over the hump. there comes a point then the water isn't strong enough to wick itself dry because your base is sloped so bad. SO if your base is flat this video proves it drains. I am doing my shower in the basement and I found a small section that slopes away from the drain so I have to preslope because I dont want to risk it.
@@stevenferro Pre slopes are a thing of the past now a days their doing closed systems so it wouldn't matter if your foundation was off level if you do it how they do it now.. Fully water proof on pan no water should soak in your pan period..
Slope or no slope. That is the question. I've watched both videos. Both to me look fine. But if I was to err on the side of caution, I would put in a preslope. Just for peace of mind.
Whether you pre-slope or not the mortar is not ever going to dry out in a shower that is in daily use. With the tile cap, water will not evaporate beyond what is held by capillary action. With tile on top and water just seeping through the grout, there will never be enough water flowing through it to wash out bacteria or mold.
My thoughts too. Even though the bucket fills up that doesn't mean there's not water in the low spots. If the pan stays saturated it will not wick up low spot water. But I guess if you're using the shower every day, the pan will stay saturated anyway causing it to fail.? I'm concerned with water remaining in low spots and creating mold/mildew.
What Bob is saying here (not that I agree) is that since moisture is drawn from wet to dry areas is that the capillary action will soak up any standing water on the liner like a sponge, as the mortar bed drains into the weeps. As it drains from the mortar into the weeps it lowers the moisture level around the drain which draws moisture from the outlying areas up through the mortar bed (or sponge)
what are the dimensions of your demonstration rig? Do you think the results would be the same if it were say twice as big or three times as big? Main reason I ask is because at around 13:20 you add a quarter inch shim to one side, unless your rig is only a foot wide ( which it appears to be larger than that) then that is less than a 1/4 inch per foot, if its a 2 foot span then you are only at 1/8 inch per foot so that's the first issue I see. Second if it is 2 ft by 2ft a 30" circle would not fit inside and then it's not even a legal shower size so the whole demonstration is pretty much a novelty at that point because it doesn't accurately depict a real world situation. It would be interesting to actually do a side by side comparison like you mentioned on Issacs video. One with pre slope and lets say one with a backwards pre slope or one that is sloped to one side since we rarely find a flat and level floor in a real world situation.
Thanks for the well-done video. As a tile contractor I've never used a preslope in the last 30+ years for this very reason. I build about 10 showers in a typical year and I've never had a problem. I've gone back to jobs to do more tile work and have seen my old showers numerous times so I know that those are still in use. That's been my experience.
Interesting experiment. Thanks. Most amazing part was the amount of work done inside the house. I kept expecting to hear a wife coming in the room and screaming "what are you doing in my dining room?" or something to that effect.
I appreciate the effort as much as anyone else but people should realize neither of these tests actually prove anything. Doing science is hard. One of the most important parts is having peers poke holes in your methodology. Here we have one test essentially testing the vaiability of a funnel. A plastic funnel with mud on top. Of coarse it works and you'll get all your water back. But that's not what your testing. Your testing whether its necessary over a non sloping funnel with mud on top. To that end it tells you nothing. On the other hand you have the non slope plastic funnel. That was saturated before hand. Look, its not exactly a huge leap to realize that there is no other possible way for this to end then to get every ounce of water back. That is what saturating is. 100% of the space that could be filled by water..... is filled by water. Where else could it go? You could've built big pools under the mud and you'd get the same result. You've already filled the mud and dead spaces with water (the fact that there probably wasnt any low dead spaces is irrelevent. If there was they would've been filled little pools with the same end result.) Neither addresses the actual issues. Im not trying to be a pro skeptic here but the issue is a lot more nuanced and difficult then this. As much as I loved mythbusters their methodology had the same issues. It wasnt science. It was just science influenced experiments. You could literally spend 4 years majoring in the ways experiments can be conceptually flawed. Researchers still get disgraced to this day by having their methods shown to be subject to basic biases.
I agree with this statement :) in the end there maybe a small influence of slope (gravity) if there are pools (gaps) in the stratum but its likely quite small. Since the influence of slope would be to increase the speed of the capillary action and time is not part of the experiment in a meaningful way... I am not a professional, so feel free to ignore my comments. I am a DIY, with my own bathroom remodel :) My take away is - slope the pan to assure efficient draining, redguard the pan to reduce influx to the pan, choose/maintain low permeating wall board, tile and grout.
I don't understand why anybody would believe what Isaac has to say anyway, he has eight or nine videos of his failures.. and just like you said he cheated on his experiment so has zero credibility
I posted this over at Isaac Ostrum video comments and curious what your thoughts are? A Case for Non-pre slope Just being the devils advocate here. First off I always put a pre-slope in my work due to avoiding any future liability but I don't think it's as important as we make it out to be. We need to keep in mind that the porous deck mud acts like a huge monolithic coarse sponge. Any monolithic material composition with particle sizes below 0.100" or less than 1/8" will have capillary action and will hold a "perched water table" at a certain level. I don't know what that level would be for deck mud(would be a great experiment as well) but it's there even if i't a 1/4". In a gardening container pot with the average potting mix you could have a perched water table as high as 3". An example may help. If you soak a long sponge in a bucket then hold it vertically letting the excess freely drain out and let stand for a while you will notice that the top is quite moist but if you squeeze the bottom then water pours out. That's the perched water table. Even with no pre-slope there is never any "standing water". I have never found much "standing water" in these demos. There may be some free water but it's mostly due to large cracks losing it's monolithic structure and or a large negative slope but not directly due to no pre-slope on a flat floor. Any water higher than the PWT is drained out of the weep holes. Moisture above the PWT is held tightly to the particles by capillary adhesive forces.
I appreciate your insight at explanation.. Perhaps others will benefit by it. It is interesting to me that you are the fourth person to comment that you do a pre slope in order to avoid liability, I have yet to pull out a saturated smelly shower, or even one that had cracked from the constant water presence that was less than 5 or 10 years old, most have been in excess of 20 years plus that were Builders grade and many of the things were done incorrect. If I ever thought that not having a pre slope would lead to a failure in a year or two then I would definitely be on board to do them, it is just not the case
The thing I see, is the pre-slope (just like the no slope) requires 100% saturation to work. Both you and Issac showed that. But if just one cup of water was put in at random all around, how much would leak back out? Putting on a layer of tile with the correct grout (by a professional, not an amateur like me) means almost no water will get in. Yes grout is porous, but done right it would only be "dampness" that SLOWLY gets through. All the shower water will run over the surface and down the drain. Like you said in your 2014 video, for the water to be able to actually run down a slope while covered in mortar/dry-pack it would have to be absolutely saturated and if THAT much water is under the tiles, then something is badly wrong and the entire shower floor will need to be torn up because grout and thinset will start crumbling.
That family guy clip! “That could be my favorite thing I’ve ever seen!” I love your videos, and your descriptions and explanations of what to do and what not to do are great! Currently in the process of building a 3x5 shower in a corner with a 90 degree curb, “poured” the pan last night, scraping excess and deficiencies tonight. Looks good so far, and with your shared knowledge I feel 100% confident in the work.
What I do, is that once my drain is set I will use scrap pieces of 1/2 cement board and install it in the shower floor around the drain. Than mix some sand mix and do a small pre slope. Just so that I have a pitch towards the drain. I try to avoid having a big shower floor. The big step up will be a negative on my customers. What are your thoughts?
You and Issac both have great content. I have been learning a lot from you guys and now feel like I can tackle my own shower pan. I hope one day you guys will be able to come together and collaborate because I think it would benefit all of your guys subscribers. Great stuff.
Perhaps there really is more than one way to skin a cat??? I watched both videos and still cannot make up my mind. Inconclusive. Someone mentioned in Tile Coach's video about making/using boxes made out of plexiglass. That would be definitive. To see in real-time how the water is moving and traveling. . . Gold! In this video we never quite know how much water is sitting at the bottom from the pre-soak. In the Tile coaches video he used some cover at the bottom...
@@johnsnetsinger7105 Depends on your definition of what *collaborate* means in YOUR head. Both Bob and Issac had a joint live stream event together so you can decide for yourself. Additionally, people can change their minds on certain products or techniques as more information and data becomes available. For example, the Earth was once considered *Center of Universe* and that everything circled around the Earth to appease the Roman Catholic Church and later Galileo (Italian astronomer) correctly asserted that our Earth circled around the Sun and was persecuted for it. Even Issac has now essentially stopped using the Schluter drains (both circular and the linear drain) since they have had many failures and since switched to preferring the Fx Flow drain which seems to be much better performing drain. Lastly, even Issac has said there is enough room in RUclips to have lots of tiler slingers on the platform and it is not a contest where it is either Issac or Bob.
wow Ive always done a pre-slope but I think Im convinced, I will definitely try to avoid doing them. Water always finds a way I guess. still its the Gravity pulling water down creating a drier area near weep holes and that drives the capillary action .
Very interesting! Years ago and still in my country we didn't had shower pan liner or preslope. We used construction plastic whether it black or clear and for all them Years our showers never failed! I lived in my house for 38 years on a no slope shower made with construction plastic and never go a water problem! Thanks for reiterating the old days!
Why is your country not named ??? is it classified Top Secret ? Is it because no one has asked ?? Ok, What Country did you for 38 years only use construction plastic, either black or clear. I think that the plastic is from Alien Space time. please send a photo of this amazing plastic sheeting , thanx.
If a serious amount of water is getting to your mortar won’t it just absorb it and slowly weep it out regardless of whether it is pre-sloped or not? Unless a small amount of saturation in the bottom of it somehow damages the drypack it seems the pre-slope is more of a precaution against a poorly or improperly installed pan-liner making it pointless if it was installed correctly in the first place. Just my two cents.
The only real advantage to having a pre slope is if your subfloor is off-kilter and you don't Rectify that before the pan material, then a pre slope would benefit you
Why not do a pre-slope?? I don't understand why it's even a debate?? The cost and labor of doing a pre-slope, is nothing compared to the cost of the entire job. Please, if you ever do my house, do a pre-slope. I'll pay the extra extra change.
Plus.... Assuming that's a 2' level, it's only an 1/8" per foot. When you add the second shim, then it's a 1/4" per foot. You're trying to convince everybody, based off your opinion. Why?
Mainly it's a moot issue nowadays because everybody is waterproofing the top of their pan material, a pre slope will be insignificant and irrelevant... But as I mentioned in the video, your pan is 100% saturated whether or not there is a slope underneath or there is no slope, breaking down the binding components of the mortar. But again, a moot issue nowadays.
Thanks for your videos. After many tiling videos, yours always prove to be the most informative. You give peace of mind in areas where I feel I might have made a mistake. As a long time handyman, I just did my 3rd shower pan in 15 years. On the latest, Worried about my pre slope being enough. just put to rest.
Yes I do the same, I have a library with 350 videos and you will see me tearing out saturated shower pans all the time... but a lot of mistakes go into those pans when they are being built including not making sure the floor is level, just because there is a failure you cannot blame it on one thing alone, operator malfunction is prevalent 👍
@@StarrTile I can't understand why you are so anti presolpe? Just do it the correct way manufacturers have it in there instructions local codes call for it...give people the correct info.
@@Tilethoughts I'm against it because it hasn't been proven to be effective... I prefaced the video by saying that I never tell people not to do a pre slope, I just show them as I have here what happens without one and Isaac did one with one and we have the same result, sorry buddy I'm not a book Soldier I question things 👍
@@StarrTile how has it not been proven to work? Everything is sloped to the drain just like your finished shower floor...why not just do your finished floor level?
@@StarrTile if you so strongly believe that a level floor under your liner is sufficient please make your finished tile floor level as well same concept.it should drain just fine with your logic.
Everyone waterproofs their shower nowadays, including the pan surface....so no water gets into pan, so preslope for what reason exactly ??? 😂 Gotta think about things rationally
This idea is so wrong it’s not even worth a comment I’m very sorry what if you have a multilevel shower ? What if you have two drains on the floor come on man buckle up and learn how to do pre slope ,Tell me what’s easy to do pre slope in the shower or make it’s all flat and level? 
I have videos where I've done pre-slopes...not it's not through lack of knowledge, it comes down to common sense, and taking time to *SHOW* the proof positive and still there's people like you out there tells me all I need to know....you can never fix ignorance
So you measure a 1/4in at the end of a 2ft level and call that correct. You just said there should be 1/4in slope per 1ft length. So should you not have 1/2in at the end of the level.
Doing experiments is a great way to learn. But yours doesn’t really show the effects of not having a pre-slope and does not prove or disprove anything. By pre-saturating the pan you’ve topped off what the mortar and pan can hold and only the excess is drained away. If you fill a glass with water to the top, and you then pour another glass of water into it, 100% of what you pour in will spill over because the glass is already full. So the fact that you recaptured what you poured in proves nothing. A pre-slope guarantees that you will have no pooling or standing water in your pan should it become saturated. A level floor could hold additional water because nothing is directing it to the drain. Also, a floor may be level when you start but after adding a couple hundred pounds of mortar or more, things can and settle and sag (if not a slab foundation) as your putting mortar in creating areas where there are low spots. Having just redone my own shower and having had to replace much of the framing due to water damage from the pan failing, I used every method I could to ensure a failure won’t occur in the future which included a pre-slope. The pan I pulled out had no pre-slope and there was significant pooling in the pan. With doing work on other people’s houses I think it’s better to be safe than sorry. In my opinion, doing everything to prevent future leakage is a good idea. If a small hole or tear is in the pan, a pre-slope will mitigate water leakage. Also not having pooling water will reduce the nasty that will inevitably occur. If you believe water will never get into the pan, then way use a liner in the first place? I think you realize that it eventually will though even though you won’t say it. Everything will eventually fail. Having multiple layers of protection will increase the life of the shower
Cool demo I’ve built upwards of 150 tile showers with no preslope no call backs Those who do a preslope I’m not saying there doing it wrong either but your demo shows no preslope is not wrong either thanks bob
@@danabennett7795 I did pvc the first 10 years of doing tile..and guess what did them all wrong no presolpes just a bunch of water holders...I can assure you presloping works.. around here the code was changed because there was so many problems with pans holding water....I'd call oatey tec support talk to those guys..look into ntca approved methods . building codes they all will tell you a presolpe is needed...and of course you can always say well star tile says it's not needed and did a test so I'm going with that..and that's your choice but and the end of the day if you're a true professional you'll do things to code and manufacturers recommendations..any thing out side of that there is nothing to back you up if you get sued .
Don't know if I thinking cornetly... If I do preslope and than read guard on the top than slop... Than if Wather penetrate slope.. Stop on read guard and goes down cuz preslope... Right? His with out preslope Wather gonna stay somwhere in lower spot... Please explain Thx
I have been a flooring professional for 30 years. You my friend are a critical thinker and what you are explaining makes absolute sense. The question now is " how saturated do you want the mortar bed to be"? You have my attention.
Wet is wet...capillary action insures all pans ( water in water out system ) will always remain wet in void of air to dry out. Going forward we all waterproof the the surface now, be it liquid topical membrane or a fleeced/clothe... Keeps any moisture out so the pan is only for a slope at surface.
@@StarrTile Im pretty convinced that keeping moisture out of the mortar bed is the answer. water needs to go directly to the drain without absorbing into surfaces period. Water needs to escape before it can gather or absorb.
@@gwynja3191 Glad someone mentioned this. I was going to suggest that Isaac, mentioned in the video, uses a membrane over the drypacked pan (please correct me if I am wrong). Wouldn't this be the best practice.? This video is very eye opening and appreciated!
@JoeySchalger @G Wyneja3 someone posted this in the comments, since you missed the entire point of his demonstration. "Everyone agrees that preslope helps. what he is trying to show you is that water will pull itself out of the drypack and into the drain without preslope. Preslope is only a requiment when you are on a concrete basement floor and the floor slopes away from the drain. In this scenario in his video, the base is perfectly flat and then the liner goes up the sides so it's like a preslope of 0 which in theory will drain. But when you have the slope of the base going away from the drain now you are relying more and more on the wicking effect to pull the water up the slope and over the hump. there comes a point then the water isn't strong enough to wick itself dry because your base is sloped so bad. SO if your base is flat this video proves it drains"
Thanks for the experiment. Since you saturated the pan before the final test, all of the water came out since by definition, a 'saturated' pan cannot hold any more water. What we don't know is how much water did it take to saturate a flat pan vs a pre-sloped pan. And as Isaac says, is there a puddle in a corner that might have held less water if there was a pre-slope. And maybe a pre-sloped pan would drain in less than the 12 min it took for yours to drain. Just continuing the discussion. By the way, there is gravity all through the pan and the mud; it's just that capillary action can overcome the gravity for a portion of the water.
@@user-xt1vs2oz3b Yes I agree. If you had a low spot in the pre-slope ( or no slope ) it could have been 100% saturated in those areas. I think it's over saturation that breaks down the deck mud. The deck mud turning to sand is from it being over saturated for an extended period from clogged weep holes. So those low spots with no pre-slope will turn to sand before long, it's not from shampoo.
I think we can all agree that your finished tile and mud bed need to slope to the drain? And would be not smart to make it level? How is making ba preslope any different every thing sloping to the drain... Now if you want to subscribe to Bob's theory let's just make everything level why have anything slope to the drain water will make its way out regardless.
I think the issue is also the fact that by the time you are relying on preslope to drain a saturated pan you have a significantly bigger problem on your hands and a failing shower. Preslope or not it's failing.
And how is that? Before liquid water proofing there was nothing standing in between. I can tell u rite now 99 percent of showers leak right threw the grout into the pan. And have been functioning like that for years upon years without the floor caving in or whatever you think might happen
I love the attitude, but I am a fan of 2 type of concrete, cracked and about to crack, then what ? I think you should slope the pan, but I would not know, mine has not failed. I think if you step on a sponge water leaves the sponge and finds its way out via gravity. Does it stand or flow ? My sponge is still wet but not like it was. What about vapor, ever see a fogged mirror that can happen inside your walls. To ignore these other cases of water penetration leads to failure eventually. What about changes in air pressure that will move water in your pan. But if you step on your pan you are pushing water out of the shower bed, even if its just the tile mortar. you could make an argument that too much water proofing is bad because you trap water when the polymer coated mortar bed fails. These details are the only difference in how long a shower lasts. Water does wick, but its not the only consideration. As far as I can tell, clogged weep holes is a much bigger issue. I had a shower that lasted over 30 years, no backer board at all, no water proofing polymers just diamond lath, mortar and a vinyl liner. No cracks no leaks. I think we get into the big box mentality and buy the new and shiny materials, when inexpensive basic materials will do the job just fine( at least for what you cant see). That is just one reason why I like StarTile videos.
You’re the reason I tried without a preslope. The logic was there. I worked with an environmental engineering company for years and knowing how chemicals travel underground through soil and other natural (and unnatural) channels the preslope argument made sense- how could it matter if the water moved through capillary action?!? So watching this was awesome and I appreciate these videos.
I've been studying all you guys for several years; you, Diblasi, Ostrum, and others. I base my common sense off of the calculations of all of your condensed wisdom. I choose to do a preslope. I don't seal the final pan top until after I've done the water test to ensure the membrane is working properly.(when you do your water test, you're gonna saturate your pan no matter what. The water is going to seep up through your drain barrel threads and weeps holes.) So after the membrane test passes, and I let it dry out for a couple days, that's when I will liquid membrane the top to seal it for the tile setting. Sure, a drain can back up and still flood your drypack,but generally speaking, all water should egress out and not backup past the p-trap. This is the process I've come to use as my ritual. I appreciate all the videos all of you make for teaching us what does and doesn't work. Keep the Info flowing!
I know this video is old but I just had to comment. I am an engineer but that doesn't make me an expert in this matter, however after watching this video and reading all the comments I have decided to do a pre-slope in my shower for these reasons: Here's a list of 15 obsolete home building practices in the U.S. that have been abandoned due to improved practices: 1. Copper pipe without protective sleeves: Copper pipes used to be installed directly under concrete slabs without protective sleeves, leading to potential corrosion and leaks. Modern practices use purpose-designed sleeves to protect pipes. 2. Asphalt felt paper as pipe wrap: Asphalt felt paper used to be wrapped around copper pipes, but it has been replaced with more durable and effective materials. 3. Traditional mortar for tile installation: Traditional sand-cement mortar used to be the standard for tile installations, but now thin-set adhesives are widely used for better adhesion and flexibility. 4. Lead-based paint: Lead-based paint, commonly used in the past, has been abandoned due to health and environmental concerns. Nowadays, lead-free alternatives are used. 5. Knob-and-tube wiring: This outdated electrical wiring method has been replaced with safer and more efficient electrical wiring systems. 6. Vermiculite insulation: Vermiculite insulation, which may contain asbestos, has been phased out due to health risks. Modern insulation materials are used instead. 7. Single-pane windows: Single-pane windows were once common but have been replaced by double-pane or energy-efficient windows for better insulation. 8. Traditional wood-burning fireplaces: Older, traditional wood-burning fireplaces are being replaced by more efficient and cleaner gas or electric fireplaces. 9. Flat roof construction without adequate drainage: Older flat roof designs with insufficient drainage have been replaced with better slope and drainage systems. 10. Paper-backed drywall: In the past, drywall with paper backing was common, but it has been replaced with moisture-resistant and mold-resistant gypsum board for increased durability. 11. Concrete without rebar reinforcement: Older concrete construction often lacked rebar reinforcement, which is now standard for added strength and structural integrity. 12. Traditional stucco: Older stucco formulations were prone to cracking and moisture issues. Modern synthetic stucco (EIFS) is more flexible and resistant to water infiltration. 13. Traditional septic systems: Outdated septic systems have been replaced with more advanced and environmentally friendly systems, such as aerobic treatment units. 14. Non-permeable vapor barriers: Traditional vapor barriers didn't allow proper moisture transfer, leading to moisture issues. Permeable vapor barriers are now used for better ventilation. 15. Traditional post-and-beam construction: Traditional heavy timber post-and-beam construction has been replaced by lighter and more versatile engineered wood products. These examples represent just a selection of the many obsolete home building practices that have been abandoned in favor of more improved and advanced methods over time. I do believe that the practice of pre-sloped mortar beds are just one more improvement over past practices.
While I agree a lot of modern practices are improvements ( asbestos NOT one of them, it was health reasons and not for practical reasons, as asbestos MADE things/products better ), your point you tried to make actually makes my point. From turn of last century drain systems for showers transitioned to "better" by introducing weep holes in drains which were used for 4-5 decades at least. whereas the IMPROVED shower system negates the weep hole system alltogether by implementing a sealed system, as I've done from at least 5 years ago with a liquid topical membrane & silicone at drain neck.....the so called divot system others adopted, or now with a product ( FLOEFEX DRAIN ) and sheet membrane. All 3 in my opinion work dependent on who installs, and all 3 do away with a weep hole mentality which is now antiquated anyway, which is YOUR point, out with old & in with new/improved. That being said you only have to answer to you, I must answer to a customer base should I fail, and I've had no failures in 24 years.
@@StarrTile No, I'm accountable to a higher power: My wife, my children and my guests that may use this shower. Your opinions are just that, opinions based on anecdotal empirical evidence you've gathered leading to your own conclusions, nothing more. You are an installer that chooses not to follow what's become an industry standard practice. In that respect you SHOULD be responsible to your customers. Industry "best" practice is this: "In a stall shower, the plumbing code requires the floor to be sloped one quarter (1/4) of an inch per foot in order to carry the water effectively to the drain. This slope, according to the TCNA Handbook is called “sloped fill” or commonly known as the pre-slope. This sloped material is installed under the pan liner (waterproofing membrane)." The industry best practice (TCNA) for installing a shower bed with a sand/mortar mix is to use a pre-slope. This practice has been widely adopted and recommended by industry experts, tile manufacturers, and building codes for several reasons: 1. **Water Management:** A pre-slope ensures proper water drainage towards the shower drain, minimizing the risk of water pooling and potential leaks. This is especially important in showers where water exposure is frequent. 2. **Waterproofing Enhancement:** While modern waterproofing materials are effective, adding a pre-slope provides an additional layer of protection against water damage. It helps prevent any water that may penetrate through the tile and grout from reaching vulnerable areas, such as the shower pan or the subfloor. 3. **Long-Term Durability:** A properly installed pre-slope can contribute to the long-term durability and performance of the shower. It helps maintain the integrity of the shower system and reduces the likelihood of water-related issues, such as mold growth and deterioration. 4. **Compliance with Building Codes:** In many regions, building codes require the use of a pre-slope in shower installations to meet specific performance standards and prevent water damage. That being said, it's essential to keep in mind that industry practices and recommendations may evolve over time. I too am guilty of selectively deviating from industry practices sometimes as with the trend in faucets whereby they have limiting devices to prevent scalding. I'm 72 years old and in my lifetime never have had to rely on such devices to 'protect me from myself'.... I remove them from the faucets when installing them.
whats the big deal? seems to show it doesn,t matter either way. The mix used has barely seen any cement so not surprisingly crumbles sometimes and is very porous
I did my tub/shower conversion about 2 years ago. I live in a 40 year old double wide. I knew I was not going to use any tile because it is so expensive that I could never recover the cost. So I planned on just a bare cement type of floor pan. The drain was forced into the right rear corner because of the structure underneath. The bath tub was 54" wide. So with the long drain path I did a pre-slope for added measure. I concluded it would not hurt and might actually help. Since there was to be no tile, the pan would be saturated regularly. The cement would deteriorate over time. So the better the drain the longer it should last. Then I ran across a product that is used to seal concrete driveways and sidewalks. I put that on it and now the water just beads up like on wax. Like putting RedGard on top of it except it is clear. Only time will tell, but will probably last longer than the double wide does.
Absolutely fascinating video, superb you proved your method is 100% the right way to do pan installations. As a plumber myself it amazes me you guys don't use ceramic shower trays , much easier , thanks again for taking the time to post the video , your a quality tradesmen👍
The shower pan liner be it CPE or PVC will not last forever if water is sitting on it. Just like everything else overtime it will deteriorate and eventually fail. However for every shower pan liner you put in without a pre slope it will fail in probably 200 years. With a pre sloped the shower pan liner will fail and 350 years. In other words, you will be long dead, as well as the original owners, and there will be nobody to sue when the pan liner fails, and pull more importantly when the building is resold with the warranty as is. With the building industry today, buildings don't last that long and neither do bathroom since they are remodeled every 15 years and rarely will a bathroom make it 30 years. This is why in my state of Michigan they eliminated the pre slope in the building codes because it is just an extra expense that's a needless to the homeowner.
Jeff D Living in a condo complex on the second floor?, I demoed a 60 year-old shower because I was afraid the shower pan had failed. No cracks in the tile, leaks onto the downstairs neighbor, or anything like that just OCD fear of liability claim. Absolutely nothing was wrong with it. Even the membrane was in pristine shape!. Chicken-wire tile too by the way....uuuughhhhhh!.
Bob why do you redguard your whole sand and cement bed in other videos if your no preslope is the way to go. Looks like the weight of the sand and cement made the center lower somewhat giving you a preslope
I started waterproofing the entirety of my for a couple of years ago, that's why the whole notion of a pre slope is a moot issue, but Isaac had challenged me after he did his video so I took him up on it
May Take 12 minutes without slope maybe with slope take 6 minutes byw u are a great tile master I like see a nice work done bcz i know isn't easy task to complete without years and years on real work field I know what's I talking about bcz I'm a plumber after 25 years I still learning from other trademan 👍
I am not a tiler, but a slope makes more logical sense than a flat surface for directing water once it gets to the bottom. Now the debate perhaps should be how much pitch. Is it .25 inches per foot or .5" based on how much faster the water drained once you went from 1/4 inch to 1/2. Again not a tiler but when you mention using common sense/logic, you were speaking my language. Lol Anyway awesome video.
As a standard plumbing code a quarter inch slope per foot is great because you have air/gravity working on the water, in an encapsulated area as you have with a mortar bed gravity is proceeded by wicking action and therefore your pan will be moist all the time regardless of any type of slope... but yes, a quarter inch per foot is what they call for, having said that everybody waterproofs the pan surface now so the whole pre-slope notion is antiquated.
@StarrTile Thank you for responding so quickly. I have watched a few of your videos and will now watch a few more to understand better the differences between your preferred method and TileCoach's. I am looking to redo my own 4x3 shower which currently is on plywood with fiberglass pan and surrounds... Any specific videos you can point me to would be helpful. Cheers.
Great Video and experimental proof, capillary action works!!! If that slab had been allowed to sit a month, like in an unrented apt, then it would have been bone dry whether the pan was level or not, capillary action trumps gravity!!! Good Job! And yes, a shower pan that is old will have a lot of smelly stuff in it due to all the tiny dead skin cells and stuff, unless it's Red Gard'd!!!
Awesome video. Never did use peples around the drain. If water can get through the mortar to the painliner, I always thought it could get through the mortar in the weep holes. Prepitches are required by code here in Florida.
I do not use pebbles and use the plastic disk too. So I agree on the point. Although the issue with no preslope is to help water from pooling in the corners of the pan or the low spots. This video shows those low spots. Now the issue is mildew growth. I have seen it on ALL non-presloped pans. All the corners will have mildew growth from under the tile and can never be removed. All of the presloped pans do not have this issue. Sure not using a preslope is easy, drains 90% of the water, but mildew growth in the grout lines is a major issue with this. This video is a prefect example of water pooling in the pan. All the water would have drained if there was a preslope going all the way to the drain. The mistake is Starr just props up the edge of the pan not the whole pan.
seems to me "capillary might be better than gravity" BUT "capillary PLUS gravity" might be even better ..... I suppose no slope is not a critical flaw , they've been done like that forever , but maybe a little slope is just a little added extra benefit , not critical , but just a bit better , can't hurt .... That's my take on it
Okay, most interesting demonstration but the comment at the end is most relevant to me: "most tilers are...waterproofing their pan surface". That's what I'm struggling with. Someone please explain why anyone would build a shower pan out of a porous, unsealed material. You wouldn't install a toilet or a sink that's porous to water.
I am **totally NOT** sold on the premise that no pre slope in needed. Goes against everything I was ever taught by numerous installers/contractors. Gravity is what governs where water travels. Period. Yes capillary action exists but gravity still directs it. Drive or hike up any river or creek bed and watch nature work. Then paddle down it in a kayak if you have the skills. I agree with much of Starr Tile's logic and his demonstration, and all... But will always include a pre slope element to avoid allowing any possibility of water finding a spot to pool up and hang out. These days with paint on waterproof membranes I fully coat the top surface of my shower pans (Hydroban), usually 3 coats to be sure to get the required thickness. Also I coat the subfloor and the pre slope. I end up with a layer cake which I believe strengthens the entire pan and keeps water from the mortar bed. So after it penetrates grout/thinset layers it hits membrane and is inclined to follow slope to drain. I agree it percolates through daypack just fine through weep holes and other egress points of drain assembly. But I see no reason to exclude slope from the equation based on this video.
If preslope doesn't at the very minimum aid in drainage of the water that reaches the pan, explain all the showers I've had to rip out that had no preslope and we're absolutely full of standing water? Not too say that a hack couldn't screw up a preslope style pan system. I for the record have never remove a leaking shower with a preslope. When using mud i do preslope unless I'm waterproofing from the top.
If your floor is perfectly flat you do not need a preslope. This video is like a preslope setting of 0. A perfectly flat base makes it very easy for the water to wick it's way to the drain. Also, since your liner is a few mm thick, when it meets the walls it slopes upwards (there is a curve at the 90 degree) so technically there no negative slope or opposing slope in the pan. it's basically a bucket on a flat floor. If you install the liner nice and tight and your floor is flat there is no reason why it shouldn't drain. You need to preslope when your base is not flat, like the concrete in your basement is built poorly, or when the carpenters build the floor poorly. Or even if there is a very small slope in the overall floor of the washroom. if some of your shower base slopes away from your drain or if the entire floor drains to one side, then you are relying on the wicking power to pull the water up the opposing slope and then into the drain. There will be a point where the wicking power is not able to pull the water up the opposing slope. the wick power is directly related to the size of the pour spaces. the smaller the pores the stronger the water can pull. Wicking is due to the water molecule being di polar. when the negatively charged oxygen in the water molecules come into contact with other negatively charged oxygen elements in the other water molecules they push away from each other. Same goes for the 2 hydrogen elements because ++ push away from each other and same goes for --. when they hit other H's in other molecules they push away from each other. You don't see anything happening at a depth but on the surface of water you can see the effect of the collisions because they are not balanced by other molecules. So the top layer of water doesn't have water on top of it to balance out the o's and the H's pushing off each other so it makes skin like behavior. insects walk on water because of this. A miniscus forms at the edge of your glass because of this. Unbalanced water molecule collisions are pushing the water up the the side of your glass. This happens at every interface between water and air. there's an unbalanced effect. When you dip a napkin in a glass of water you will see the water rise up the napkin because of the energy that the collisions are creating at the air/water interface. The smaller the pores the higher it will rise because the energy has to carry less weight. larger pore spaces means a larger amount of water needed to fill the pore which is heavier. So the size of the poor spaces in the dry pack can only pull water up a certain amount. If your base is ever poorly sloped then there's a chance that the wick can't drain the drypack. This action also works horizontally, if the water falls into the drain then the pore spaces next to the drain have air in them and the pores adjacent to those pores are full of water so it pushes in that direction. So a flat surface like this experiment, a 0 slope will work. if you are ever uncertain, just preslope it and don't risk it. great video.
I still believe the preslope will allow more water to find its way out , however i am going to waterproof my shower beds to reduce the amount of water that makes it into the shower base, and hopefully reduce mold build up under the floor tile
awesome video.... so I saw a video of you applying Red Guard... is this where I would apply it ? onto the mortar ?and then after 3 layers.... next is thinset for tiles ?
@@StarrTile would also like to ask you about the type of grout to use on floor tile in the shower floor. should we be using epoxy grout or something else ? TIA
I know this vid is 2 years old, but it reminded me of an experiment back in middle school. If you take a stalk of celery and put it in food-colored water, the stalk will suck up the liquid far above the lowest point of the container. It’s an easier visualization of capillary action. So no, water doesn’t always go to the lowest place.
Not a very good test. The shims only tilt the table in one direction. They don't provide a slope towards the drain. This means that the water not sloped towards the drain is providing resistance to the water directly upstream of the drain. Not to mention the bubbled-up liner that results in water having to go over hills to get to the drain.
terribly flawed experiments, basically rigged the first 1, the 2nd was set up already containing the problem to start with as if it was a consistent variable. your argument is completely missing the point. No offense but youre not even asking the right questions bud. Maybe this is for views or IDK........... IF YOUR BED IS COMPLETELY SATURATED AND THERE IS RESIDUAL WATER IN YOUR PAN THEN IT"S ALREADY FAILED AND the problem there is you dont see why or how thats a problem........ IT"S NOT ROCKET SCIENCE GUYS. People spend too much $$$ on shit for amateurs to gamble with and risk doubling/tripling the cost just bc a dudes argument for how shit may not always run downhill is enough to talk himself out of a half days work and thats taking your sweet precious time.
SO MR STARR. are you now using redguard over the entire dry pack? i know at one time you were just doing like 6 inches around perimeter. what i dont get is the words " mold sandwich" i see this phrase every time someone asks can you use a liquid membrane over a water in water out system, well why isnt this mold sammy happening in a schluter type system? i guess the only difference would be that in a schluter system the water under tile is making its way to the drain but afaik thats not happening as the water just evaporates, but if it did then just dont put liquid membrane in the general vacinity of the drain in a liner system and that water would also drop down to weep holes...
It’s not just capillary action, it’s hydronic pressure, the pre slope is just for incase but with that said, water won’t wick to the pan just because. Experiment is flawed. It’s not the end all of you don’t preslope but over time you can end up having an issue a extra 30 minutes can 100% prevent. The mortar bed is porous and if it is to get completely saturated and make it to the rubber liner then there’s a good chance it’s not goi g to come all the way back up thru it or wick it’s way to the drain
Hi this is nice testing but it is not in real life testing. First you supposed to build the regular size shower not 3 by 3 feet shower. If is smaller water can penetrate much faster and easier because the distance to the drain is shorter. I think it is depends where you have the drain. If you have linear drain 4 inch from the wall you probably need to do that pre slope because water can set across the drain wall if you don’t have the pre slope. This is very good question you need to have it pre slope or not.
Pre-slop or not pre-slop? I am remodeling my own bathroom and this question got me puzzled all over. Could not get to point why should I do this sandwich, so went to no pre-slop. But very pleased to find discussion here on this topic, that helped me finally to get to the point why many care for pre-slop. 1: Let water to get out from low spots in top layer of mortar. 2. To avoid liability. Thanks so much for this clarification! But I am not about to redo none slop pan that I already did. Just curious, I painted the the top layer with waterproofed paint, what difference it might make? Also I painted under the liner all the sides of the shower to prevent from tiny ants coming because I saw them under old pan when removing it. Those beasts are the nuisance in FL and they get to any place in the house where they have enough moisture. The shower is one one of them and I wonder that no one is offering the way to fight those creatures.
StarrTile, The evidence is on you to prove that a pre-slope shower pan doesn't improve overall function. You've just shown us how a shower pan works with no pre-slope.
Evidence that a preslope works is on Issac's video that I linked..Evidence it doesn't help is here... I am not the Trier of fact I simply present the evidence
this is the first time ive heard of people putting rocks and pebbles to stop the weep holes from getting clogged. Never heard of it, its not in the handbook. Wonder who thought of that.
It's a fairly common practice in Florida...well, used to be. Now, Florida Building Code mandates that ALL shower pans MUST BE pre-pitched before installing your pan liner. They even have a pre-pitch inspection you have to call in before placing your liner. It's ridiculous! It wastes a whole day before you can continue with the remodel
I don’t see how that would help unless you covered the whole bottom of the pan with a thin layer of gravel. If the water is going to wick through the mortar, it seems like it could wick through the mortar that blocks the weep holes.
@@MoneyManHolmes and that is the irony about people who say water will get into your pan material which is mortar mix but they dispute that it can get into your mortar mix through the weep holes, so freaking illogical
Just open the Oatey manual and it shows the pebbles and pre-slope. Not debating good or bad, just noting it’s in the docs. www.oatey.com/ASSETS/DOCUMENTS/ITEMS/EN/showerpanliner.pdf
What am i missing? It seems if the water happen to break through liner, then it will just go through the preslope mortar as well and end up on the wood or slab. 🤔
I suggest we do comparison experiments for saturated pan with/without pre-slope to see if there is a difference in the amount of new water that replaces old water. First let's use water with certain concentration of ink to saturate both shower pan mud beds, then use clean water to 'wash' the mud beds to see if there is a difference in the color of water coming out of both mud beds...
That's a great idea and an experiment like that would be the only way to truly know if water is cycling. Having said that it's a moot issue because everyone waterproof their pan surface now so no water gets in to begin with
to my understanding, you said the soapy shower water deteriorates the sand-mortar mix. It deteriorates the cement components and leaves the sand behind. So anytime water gets into the mortar mix is bad? Is this correct? or is it ok for the mortar mix to get saturated? I realize that you use thin set around drain and you mention it helps the redguard waterproofing to adhere better. that was said in another video of yours. then you coat with redguard. This is to ensure that water never actually enters the mortar bed but it is there as a backup? This is my understanding of the video, am i understanding correctly? This is very helpful to me.
Help me understand, the majority of the water drained from the top of the deck mud to the weep holes on top, yes? Very little is going to permeate the mud , especially because you rightly pre saturated it. It’s the path of least resistance. Heat moved from hot to cold, water moves from wet to dry. Only a small amount is going to move down through the mud . Once there the hydrostatic pressure is a weak force. Any “ trapped “ water will move to the driest place by capillary action. No pre slope needed.
So I made a video years ago called "pre slope explained".... probably still on my channel and it was kind of off the cuff type of video that I did because I was frustrated people pushing back on my theory. Fast forward to the last 3 or 4 years, everybody waterproofs the surface of the pan so the pre-slope idea and weep holes are as Antiquated as a phone booth.
Thanks for the test. Seems like there's a lot of debate on whether to pre slope. I'll stick with the recommendations of the American standard institute of ceramic tile as well as the tile institute of North America. I'm going to guess they collectively have more knowledge and experience then any one person. They recommended pre slope. Furthermore its also an insurance policy against potential litigation. It's going to be hard to argue against a recommendation from such Institutes which more often than not are basis for standard practices/code.
You are free to do whatever you like, code aside because there is no code where I'm at to do a pre slope, the reason I did the experiment is to prove it's irrelevant, if not for everyone else then at least to myself. And because entities recommend something isn't because they feel it's necessary, they do it to CYA against operator malfunction...same for the hot label on coffee cups. Legal process and litigation is the last thing I'm worried about, my showers are built 10times better than what I tore out, and those ppl selling products or recommend something will never go to bat for you regardless, they have no desire to defend *you*...lawyers will be sure to disseminate every step you failed at, not just this one. Having said all of that, it's a moot issue anyway since tile guys are waterproofing their pans now, so a preslope is irrelevant.
Thank you Bob, I’m converting my tub to shower on concrete slab, and will apply a few coats of waterproofing on the mud base before laying the tiles. Keep these videos coming.
Does the mortar adhere to the rubber underlayment like glue after it dries? Or after the mortar dries and shrinks a little, would it be possible for some space or gaps to occur which then the pre slope would always be aiming that residual water back into the drain?
Nice video but I'm still doing a pre-slope. Your demonstration is defined by there always being some amount of water in the pan. I'd like to have my pan become as dry as possible much like the way a tub or sink drains until it is dry. Also, I get the use of "pebbles" but never felt the need-so at least you verified that especially since most drains are centrally located and will see the most force from people standing on or close to it. (pebbles making for a weak spot).
Honestly I have stopped talking about pre slopes going back probably 5 years....the kool-aid is too strong. But I will say this, with wicking action your pan will never ever be dry...pebbles can clog holes easier than mortar because pebbles are dense. And as you mentioned cause a weak spot. Intuitively it makes no sense since 1/4" per foot is a plumbing code for gravity fed water in a sewer line, not encapsulated with 200pounds of mortar. So critical thinking is necessary to overcome the myth fed theory. Having said all that nobody does the pre-slope anymore because we have transitioned to a sealed system in the last 3-4 years, although I started creating my own sealed system about 7 or 8 years ago and it is Bulletproof. This leaves preslopes as irrelevant as a phone booth.
*Feel free to discuss amongst yourselves..Issac's video was flawed since he used a mat below mortar bed which gave a false result..., I have stated my opinion on this subject many more times than I care to, I have done a demo and stated my opinion again on all the aspects of a pre slope, it's a dead horse now and I won't entertain any questions or debate the subject here*
Well, what you DONT do, is apply caulk while screwing the cap on in between, which is what I did. Ow I can’t sleep thinking that there’s a shower I built, just waiting to fail.
It's all in the book preslope is always required
Laces out
Every shower I tear out with no preslope, smells terrible, which is caused by bacteria, this is my main complaint. At end of day, if water isn't leaving the pan and destroying everything, you are good(ish)
I agree that the issue is not that the dry pack itself clogs the weep holes. However, isn't it possible that over time, with the addition of detergent residue, mineral deposits and perhaps mold, the mortar (in the weep holes) eventually becomes less permeable or impermeable?
I love tile drama lol! All of you main guys putting out videos are awesome! I applaud you all. Being a contractor myself I don’t have the nerve to do videos so my hat is off to y’all!
Capillary action is stronger than gravity, but when complete saturation of water in mortar occurs at some point, it would seem helpful to have a slope to aid in drainage purposes.
If it gets fully saturated, then you have a bigger issue than not having a pre slope.
Everyone agrees that preslope helps. what he is trying to show you is that water will pull itself out of the drypack and into the drain without preslope. Preslope is only a requiment when you are on a concrete basement floor and the floor slopes away from the drain. In this scenario in his video, the base is perfectly flat and then the liner goes up the sides so it's like a preslope of 0 which in theory will drain. But when you have the slope of the base going away from the drain now you are relying more and more on the wicking effect to pull the water up the slope and over the hump. there comes a point then the water isn't strong enough to wick itself dry because your base is sloped so bad. SO if your base is flat this video proves it drains. I am doing my shower in the basement and I found a small section that slopes away from the drain so I have to preslope because I dont want to risk it.
@@stevenferro Pre slopes are a thing of the past now a days their doing closed systems so it wouldn't matter if your foundation was off level if you do it how they do it now.. Fully water proof on pan no water should soak in your pan period..
Slope or no slope. That is the question. I've watched both videos. Both to me look fine. But if I was to err on the side of caution, I would put in a preslope. Just for peace of mind.
Everyone just convert to topical membranes and move on. I started off doing preslopes then went topical. Won't go back.
Whether you pre-slope or not the mortar is not ever going to dry out in a shower that is in daily use. With the tile cap, water will not evaporate beyond what is held by capillary action. With tile on top and water just seeping through the grout, there will never be enough water flowing through it to wash out bacteria or mold.
So then, how do we prevent this from happening? Redgard the top of the mortar pan?
@@goskidmark I would. Either that or you could also use one of the other products like the kerdi or something.
But you can red guard the dry pack ! 😉👍🏼
Mold will not grow on mortar. Nor will it grow anaerobically.
Get a preformed pan. End if story.
how do you think the weep holes will drain water if water is stuck in a corner cause you don't have pre slope
My thoughts too. Even though the bucket fills up that doesn't mean there's not water in the low spots. If the pan stays saturated it will not wick up low spot water. But I guess if you're using the shower every day, the pan will stay saturated anyway causing it to fail.? I'm concerned with water remaining in low spots and creating mold/mildew.
Doesn't water ALWAYS find the lowest place it can get to? Preslope helps a lot. 25 years everyone. I know how it works.
What Bob is saying here (not that I agree) is that since moisture is drawn from wet to dry areas is that the capillary action will soak up any standing water on the liner like a sponge, as the mortar bed drains into the weeps. As it drains from the mortar into the weeps it lowers the moisture level around the drain which draws moisture from the outlying areas up through the mortar bed (or sponge)
ALWAYS PRE SLOPE
what are the dimensions of your demonstration rig? Do you think the results would be the same if it were say twice as big or three times as big? Main reason I ask is because at around 13:20 you add a quarter inch shim to one side, unless your rig is only a foot wide ( which it appears to be larger than that) then that is less than a 1/4 inch per foot, if its a 2 foot span then you are only at 1/8 inch per foot so that's the first issue I see. Second if it is 2 ft by 2ft a 30" circle would not fit inside and then it's not even a legal shower size so the whole demonstration is pretty much a novelty at that point because it doesn't accurately depict a real world situation. It would be interesting to actually do a side by side comparison like you mentioned on Issacs video. One with pre slope and lets say one with a backwards pre slope or one that is sloped to one side since we rarely find a flat and level floor in a real world situation.
Lol nice catch about the shim
It is actually mandated by Florida Building Code to pre-pitch your shower pan before installing a pan liner now...at least in my County
yes I work in alachua county fl, and pre slope is required
Preslopes make me feel good, plus they help me in defending myself when I get sued.
@Matt The Builder. Exactly, that's the point I was trying to make.
If your shower doesn't fail, will you still get sued?
@@johnnybear111 if your shower isnt pre sloped, is it gonna fail?
We waterproof entire shower now, making the pre slope a moot issue
Thanks for the well-done video. As a tile contractor I've never used a preslope in the last 30+ years for this very reason. I build about 10 showers in a typical year and I've never had a problem. I've gone back to jobs to do more tile work and have seen my old showers numerous times so I know that those are still in use. That's been my experience.
TileCoach > StarrTile
Interesting experiment. Thanks. Most amazing part was the amount of work done inside the house. I kept expecting to hear a wife coming in the room and screaming "what are you doing in my dining room?" or something to that effect.
I appreciate the effort as much as anyone else but people should realize neither of these tests actually prove anything. Doing science is hard. One of the most important parts is having peers poke holes in your methodology. Here we have one test essentially testing the vaiability of a funnel. A plastic funnel with mud on top. Of coarse it works and you'll get all your water back. But that's not what your testing. Your testing whether its necessary over a non sloping funnel with mud on top. To that end it tells you nothing.
On the other hand you have the non slope plastic funnel. That was saturated before hand. Look, its not exactly a huge leap to realize that there is no other possible way for this to end then to get every ounce of water back. That is what saturating is. 100% of the space that could be filled by water..... is filled by water. Where else could it go? You could've built big pools under the mud and you'd get the same result. You've already filled the mud and dead spaces with water (the fact that there probably wasnt any low dead spaces is irrelevent. If there was they would've been filled little pools with the same end result.) Neither addresses the actual issues. Im not trying to be a pro skeptic here but the issue is a lot more nuanced and difficult then this.
As much as I loved mythbusters their methodology had the same issues. It wasnt science. It was just science influenced experiments. You could literally spend 4 years majoring in the ways experiments can be conceptually flawed. Researchers still get disgraced to this day by having their methods shown to be subject to basic biases.
I agree with this statement :) in the end there maybe a small influence of slope (gravity) if there are pools (gaps) in the stratum but its likely quite small. Since the influence of slope would be to increase the speed of the capillary action and time is not part of the experiment in a meaningful way... I am not a professional, so feel free to ignore my comments. I am a DIY, with my own bathroom remodel :) My take away is - slope the pan to assure efficient draining, redguard the pan to reduce influx to the pan, choose/maintain low permeating wall board, tile and grout.
I don't understand why anybody would believe what Isaac has to say anyway, he has eight or nine videos of his failures..
and just like you said he cheated on his experiment so has zero credibility
Yes indeed he has quite a few failures...coaching is a tuff gig 😉
I posted this over at Isaac Ostrum video comments and curious what your thoughts are?
A Case for Non-pre slope
Just being the devils advocate here. First off I always put a pre-slope in my work due to avoiding any future liability but I don't think it's as important as we make it out to be. We need to keep in mind that the porous deck mud acts like a huge monolithic coarse sponge. Any monolithic material composition with particle sizes below 0.100" or less than 1/8" will have capillary action and will hold a "perched water table" at a certain level. I don't know what that level would be for deck mud(would be a great experiment as well) but it's there even if i't a 1/4". In a gardening container pot with the average potting mix you could have a perched water table as high as 3". An example may help. If you soak a long sponge in a bucket then hold it vertically letting the excess freely drain out and let stand for a while you will notice that the top is quite moist but if you squeeze the bottom then water pours out. That's the perched water table. Even with no pre-slope there is never any "standing water". I have never found much "standing water" in these demos. There may be some free water but it's mostly due to large cracks losing it's monolithic structure and or a large negative slope but not directly due to no pre-slope on a flat floor. Any water higher than the PWT is drained out of the weep holes. Moisture above the PWT is held tightly to the particles by capillary adhesive forces.
I appreciate your insight at explanation.. Perhaps others will benefit by it.
It is interesting to me that you are the fourth person to comment that you do a pre slope in order to avoid liability, I have yet to pull out a saturated smelly shower, or even one that had cracked from the constant water presence that was less than 5 or 10 years old, most have been in excess of 20 years plus that were Builders grade and many of the things were done incorrect. If I ever thought that not having a pre slope would lead to a failure in a year or two then I would definitely be on board to do them, it is just not the case
@@StarrTile 'perched water table' is the correct description.
The thing I see, is the pre-slope (just like the no slope) requires 100% saturation to work. Both you and Issac showed that. But if just one cup of water was put in at random all around, how much would leak back out? Putting on a layer of tile with the correct grout (by a professional, not an amateur like me) means almost no water will get in. Yes grout is porous, but done right it would only be "dampness" that SLOWLY gets through. All the shower water will run over the surface and down the drain. Like you said in your 2014 video, for the water to be able to actually run down a slope while covered in mortar/dry-pack it would have to be absolutely saturated and if THAT much water is under the tiles, then something is badly wrong and the entire shower floor will need to be torn up because grout and thinset will start crumbling.
i think thats the point hes making the shower has to be replaced eitherway if your having this problem so why do the preslope
That family guy clip! “That could be my favorite thing I’ve ever seen!” I love your videos, and your descriptions and explanations of what to do and what not to do are great! Currently in the process of building a 3x5 shower in a corner with a 90 degree curb, “poured” the pan last night, scraping excess and deficiencies tonight. Looks good so far, and with your shared knowledge I feel 100% confident in the work.
What I do, is that once my drain is set I will use scrap pieces of 1/2 cement board and install it in the shower floor around the drain. Than mix some sand mix and do a small pre slope. Just so that I have a pitch towards the drain. I try to avoid having a big shower floor. The big step up will be a negative on my customers. What are your thoughts?
You and Issac both have great content. I have been learning a lot from you guys and now feel like I can tackle my own shower pan. I hope one day you guys will be able to come together and collaborate because I think it would benefit all of your guys subscribers. Great stuff.
Perhaps there really is more than one way to skin a cat???
I watched both videos and still cannot make up my mind. Inconclusive.
Someone mentioned in Tile Coach's video about making/using boxes made out of plexiglass. That would be definitive. To see in real-time how the water is moving and traveling. . . Gold!
In this video we never quite know how much water is sitting at the bottom from the pre-soak. In the Tile coaches video he used some cover at the bottom...
They will never collaborate because Isaac does it right and this guy does not.
@@johnsnetsinger7105 Depends on your definition of what *collaborate* means in YOUR head. Both Bob and Issac had a joint live stream event together so you can decide for yourself. Additionally, people can change their minds on certain products or techniques as more information and data becomes available. For example, the Earth was once considered *Center of Universe* and that everything circled around the Earth to appease the Roman Catholic Church and later Galileo (Italian astronomer) correctly asserted that our Earth circled around the Sun and was persecuted for it. Even Issac has now essentially stopped using the Schluter drains (both circular and the linear drain) since they have had many failures and since switched to preferring the Fx Flow drain which seems to be much better performing drain. Lastly, even Issac has said there is enough room in RUclips to have lots of tiler slingers on the platform and it is not a contest where it is either Issac or Bob.
Man i love these mockup videos. I've been lied to my entire life! lol I even used those rocks around the drain to keep the weep holes open! Lol
Leave the comments open Starr lol. I wanna see others opinions and facts to see different aspects great video as always
Comments will stay open , I just won't debate the issue any further
wow Ive always done a pre-slope but I think Im convinced, I will definitely try to avoid doing them. Water always finds a way I guess. still its the Gravity pulling water down creating a drier area near weep holes and that drives the capillary action .
You answered your own question. Absence of any additional water...the bed will dry towards the drain/weeping system...via capillary action.
Very interesting! Years ago and still in my country we didn't had shower pan liner or preslope. We used construction plastic whether it black or clear and for all them Years our showers never failed! I lived in my house for 38 years on a no slope shower made with construction plastic and never go a water problem! Thanks for reiterating the old days!
Why is your country not named ??? is it classified Top Secret ? Is it because no one has asked ?? Ok, What Country did you for 38 years only use construction plastic, either black or clear. I think that the plastic is from Alien Space time.
please send a photo of this amazing plastic sheeting , thanx.
Your not supposed to use pebbles. It should be gravel.. 1/4" and 1/2".… those holes are to small for a pebble to clog them..
If a serious amount of water is getting to your mortar won’t it just absorb it and slowly weep it out regardless of whether it is pre-sloped or not? Unless a small amount of saturation in the bottom of it somehow damages the drypack it seems the pre-slope is more of a precaution against a poorly or improperly installed pan-liner making it pointless if it was installed correctly in the first place. Just my two cents.
The only real advantage to having a pre slope is if your subfloor is off-kilter and you don't Rectify that before the pan material, then a pre slope would benefit you
Epoxy grout with a non porous material such as porcelain
Why not do a pre-slope??
I don't understand why it's even a debate?? The cost and labor of doing a pre-slope, is nothing compared to the cost of the entire job. Please, if you ever do my house, do a pre-slope. I'll pay the extra extra change.
Plus....
Assuming that's a 2' level, it's only an 1/8" per foot. When you add the second shim, then it's a 1/4" per foot.
You're trying to convince everybody, based off your opinion.
Why?
Mainly it's a moot issue nowadays because everybody is waterproofing the top of their pan material, a pre slope will be insignificant and irrelevant...
But as I mentioned in the video, your pan is 100% saturated whether or not there is a slope underneath or there is no slope, breaking down the binding components of the mortar. But again, a moot issue nowadays.
Thanks for your videos. After many tiling videos, yours always prove to be the most informative. You give peace of mind in areas where I feel I might have made a mistake.
As a long time handyman, I just did my 3rd shower pan in 15 years. On the latest, Worried about my pre slope being enough. just put to rest.
I love this guy he speaks alot of trash then ends up backing it up unlike 99.99% of tile guys keep it up 👍🏼 your the best !
I tear showers out all the time with no presolpes the all hold water...think what you want but they are needed.
Yes I do the same, I have a library with 350 videos and you will see me tearing out saturated shower pans all the time... but a lot of mistakes go into those pans when they are being built including not making sure the floor is level, just because there is a failure you cannot blame it on one thing alone, operator malfunction is prevalent 👍
@@StarrTile I can't understand why you are so anti presolpe? Just do it the correct way manufacturers have it in there instructions local codes call for it...give people the correct info.
@@Tilethoughts I'm against it because it hasn't been proven to be effective... I prefaced the video by saying that I never tell people not to do a pre slope, I just show them as I have here what happens without one and Isaac did one with one and we have the same result, sorry buddy I'm not a book Soldier I question things 👍
@@StarrTile how has it not been proven to work? Everything is sloped to the drain just like your finished shower floor...why not just do your finished floor level?
@@StarrTile if you so strongly believe that a level floor under your liner is sufficient please make your finished tile floor level as well same concept.it should drain just fine with your logic.
Do it right. If you don't want a stinky shower a few months down the road, do the pre-slope!
Everyone waterproofs their shower nowadays, including the pan surface....so no water gets into pan, so preslope for what reason exactly ??? 😂
Gotta think about things rationally
This idea is so wrong it’s not even worth a comment I’m very sorry what if you have a multilevel shower ? What if you have two drains on the floor come on man buckle up and learn how to do pre slope ,Tell me what’s easy to do pre slope in the shower or make it’s all flat and level? 
I have videos where I've done pre-slopes...not it's not through lack of knowledge, it comes down to common sense, and taking time to *SHOW* the proof positive and still there's people like you out there tells me all I need to know....you can never fix ignorance
So you measure a 1/4in at the end of a 2ft level and call that correct. You just said there should be 1/4in slope per 1ft length. So should you not have 1/2in at the end of the level.
1/4 per foot, one foot is one side of the pan
Doing experiments is a great way to learn. But yours doesn’t really show the effects of not having a pre-slope and does not prove or disprove anything.
By pre-saturating the pan you’ve topped off what the mortar and pan can hold and only the excess is drained away. If you fill a glass with water to the top, and you then pour another glass of water into it, 100% of what you pour in will spill over because the glass is already full.
So the fact that you recaptured what you poured in proves nothing.
A pre-slope guarantees that you will have no pooling or standing water in your pan should it become saturated. A level floor could hold additional water because nothing is directing it to the drain.
Also, a floor may be level when you start but after adding a couple hundred pounds of mortar or more, things can and settle and sag (if not a slab foundation) as your putting mortar in creating areas where there are low spots.
Having just redone my own shower and having had to replace much of the framing due to water damage from the pan failing, I used every method I could to ensure a failure won’t occur in the future which included a pre-slope. The pan I pulled out had no pre-slope and there was significant pooling in the pan.
With doing work on other people’s houses I think it’s better to be safe than sorry. In my opinion, doing everything to prevent future leakage is a good idea. If a small hole or tear is in the pan, a pre-slope will mitigate water leakage. Also not having pooling water will reduce the nasty that will inevitably occur.
If you believe water will never get into the pan, then way use a liner in the first place? I think you realize that it eventually will though even though you won’t say it. Everything will eventually fail. Having multiple layers of protection will increase the life of the shower
Little did I know there was so much drama in the tile world
Cool demo
I’ve built upwards of 150 tile showers with no preslope no call backs
Those who do a preslope I’m not saying there doing it wrong either but your demo shows no preslope is not wrong either thanks bob
That doesn't prove you did 150 showers the right way...
Amos R let me guess you are a presloper
Well good for you
@@danabennett7795 I don't do pvc liners surface membranes schluter or laticrete products.
Then if you don't use PVC products then how do you know that no preslpoe is wrong ?
@@danabennett7795 I did pvc the first 10 years of doing tile..and guess what did them all wrong no presolpes just a bunch of water holders...I can assure you presloping works.. around here the code was changed because there was so many problems with pans holding water....I'd call oatey tec support talk to those guys..look into ntca approved methods . building codes they all will tell you a presolpe is needed...and of course you can always say well star tile says it's not needed and did a test so I'm going with that..and that's your choice but and the end of the day if you're a true professional you'll do things to code and manufacturers recommendations..any thing out side of that there is nothing to back you up if you get sued .
Don't know if I thinking cornetly... If I do preslope and than read guard on the top than slop... Than if Wather penetrate slope.. Stop on read guard and goes down cuz preslope... Right? His with out preslope Wather gonna stay somwhere in lower spot... Please explain
Thx
I waterproof the entire surface of the shower so no water will ever see the mortar mix, that's why I don't do a pre slope because it's irrelevant
Yes but Wather stay i nie low spot with out preslope right? And with the time... Gonna be bad smell there and moulding..
I have been a flooring professional for 30 years. You my friend are a critical thinker and what you are explaining makes absolute sense. The question now is " how saturated do you want the mortar bed to be"? You have my attention.
Wet is wet...capillary action insures all pans ( water in water out system ) will always remain wet in void of air to dry out.
Going forward we all waterproof the the surface now, be it liquid topical membrane or a fleeced/clothe...
Keeps any moisture out so the pan is only for a slope at surface.
@@StarrTile Im pretty convinced that keeping moisture out of the mortar bed is the answer. water needs to go directly to the drain without absorbing into surfaces period. Water needs to escape before it can gather or absorb.
@@gwynja3191 Glad someone mentioned this. I was going to suggest that Isaac, mentioned in the video, uses a membrane over the drypacked pan (please correct me if I am wrong). Wouldn't this be the best practice.? This video is very eye opening and appreciated!
@JoeySchalger @G Wyneja3
someone posted this in the comments, since you missed the entire point of his demonstration.
"Everyone agrees that preslope helps. what he is trying to show you is that water will pull itself out of the drypack and into the drain without preslope. Preslope is only a requiment when you are on a concrete basement floor and the floor slopes away from the drain. In this scenario in his video, the base is perfectly flat and then the liner goes up the sides so it's like a preslope of 0 which in theory will drain. But when you have the slope of the base going away from the drain now you are relying more and more on the wicking effect to pull the water up the slope and over the hump. there comes a point then the water isn't strong enough to wick itself dry because your base is sloped so bad. SO if your base is flat this video proves it drains"
Thanks for the experiment. Since you saturated the pan before the final test, all of the water came out since by definition, a 'saturated' pan cannot hold any more water. What we don't know is how much water did it take to saturate a flat pan vs a pre-sloped pan. And as Isaac says, is there a puddle in a corner that might have held less water if there was a pre-slope. And maybe a pre-sloped pan would drain in less than the 12 min it took for yours to drain. Just continuing the discussion. By the way, there is gravity all through the pan and the mud; it's just that capillary action can overcome the gravity for a portion of the water.
Came here to say this
@@user-xt1vs2oz3b Yes I agree. If you had a low spot in the pre-slope ( or no slope ) it could have been 100% saturated in those areas. I think it's over saturation that breaks down the deck mud. The deck mud turning to sand is from it being over saturated for an extended period from clogged weep holes. So those low spots with no pre-slope will turn to sand before long, it's not from shampoo.
I think we can all agree that your finished tile and mud bed need to slope to the drain? And would be not smart to make it level? How is making ba preslope any different every thing sloping to the drain... Now if you want to subscribe to Bob's theory let's just make everything level why have anything slope to the drain water will make its way out regardless.
I will do preslope in my own shower
I think the issue is also the fact that by the time you are relying on preslope to drain a saturated pan you have a significantly bigger problem on your hands and a failing shower. Preslope or not it's failing.
And how is that? Before liquid water proofing there was nothing standing in between. I can tell u rite now 99 percent of showers leak right threw the grout into the pan. And have been functioning like that for years upon years without the floor caving in or whatever you think might happen
I love the attitude, but I am a fan of 2 type of concrete, cracked and about to crack, then what ? I think you should slope the pan, but I would not know, mine has not failed. I think if you step on a sponge water leaves the sponge and finds its way out via gravity. Does it stand or flow ? My sponge is still wet but not like it was. What about vapor, ever see a fogged mirror that can happen inside your walls. To ignore these other cases of water penetration leads to failure eventually. What about changes in air pressure that will move water in your pan. But if you step on your pan you are pushing water out of the shower bed, even if its just the tile mortar. you could make an argument that too much water proofing is bad because you trap water when the polymer coated mortar bed fails. These details are the only difference in how long a shower lasts. Water does wick, but its not the only consideration. As far as I can tell, clogged weep holes is a much bigger issue. I had a shower that lasted over 30 years, no backer board at all, no water proofing polymers just diamond lath, mortar and a vinyl liner. No cracks no leaks. I think we get into the big box mentality and buy the new and shiny materials, when inexpensive basic materials will do the job just fine( at least for what you cant see). That is just one reason why I like StarTile videos.
You’re the reason I tried without a preslope. The logic was there. I worked with an environmental engineering company for years and knowing how chemicals travel underground through soil and other natural (and unnatural) channels the preslope argument made sense- how could it matter if the water moved through capillary action?!? So watching this was awesome and I appreciate these videos.
I've been studying all you guys for several years; you, Diblasi, Ostrum, and others.
I base my common sense off of the calculations of all of your condensed wisdom.
I choose to do a preslope. I don't seal the final pan top until after I've done the water test to ensure the membrane is working properly.(when you do your water test, you're gonna saturate your pan no matter what. The water is going to seep up through your drain barrel threads and weeps holes.)
So after the membrane test passes, and I let it dry out for a couple days, that's when I will liquid membrane the top to seal it for the tile setting.
Sure, a drain can back up and still flood your drypack,but generally speaking, all water should egress out and not backup past the p-trap.
This is the process I've come to use as my ritual.
I appreciate all the videos all of you make for teaching us what does and doesn't work.
Keep the Info flowing!
I know this video is old but I just had to comment. I am an engineer but that doesn't make me an expert in this matter, however after watching this video and reading all the comments I have decided to do a pre-slope in my shower for these reasons:
Here's a list of 15 obsolete home building practices in the U.S. that have been abandoned due to improved practices:
1. Copper pipe without protective sleeves: Copper pipes used to be installed directly under concrete slabs without protective sleeves, leading to potential corrosion and leaks. Modern practices use purpose-designed sleeves to protect pipes.
2. Asphalt felt paper as pipe wrap: Asphalt felt paper used to be wrapped around copper pipes, but it has been replaced with more durable and effective materials.
3. Traditional mortar for tile installation: Traditional sand-cement mortar used to be the standard for tile installations, but now thin-set adhesives are widely used for better adhesion and flexibility.
4. Lead-based paint: Lead-based paint, commonly used in the past, has been abandoned due to health and environmental concerns. Nowadays, lead-free alternatives are used.
5. Knob-and-tube wiring: This outdated electrical wiring method has been replaced with safer and more efficient electrical wiring systems.
6. Vermiculite insulation: Vermiculite insulation, which may contain asbestos, has been phased out due to health risks. Modern insulation materials are used instead.
7. Single-pane windows: Single-pane windows were once common but have been replaced by double-pane or energy-efficient windows for better insulation.
8. Traditional wood-burning fireplaces: Older, traditional wood-burning fireplaces are being replaced by more efficient and cleaner gas or electric fireplaces.
9. Flat roof construction without adequate drainage: Older flat roof designs with insufficient drainage have been replaced with better slope and drainage systems.
10. Paper-backed drywall: In the past, drywall with paper backing was common, but it has been replaced with moisture-resistant and mold-resistant gypsum board for increased durability.
11. Concrete without rebar reinforcement: Older concrete construction often lacked rebar reinforcement, which is now standard for added strength and structural integrity.
12. Traditional stucco: Older stucco formulations were prone to cracking and moisture issues. Modern synthetic stucco (EIFS) is more flexible and resistant to water infiltration.
13. Traditional septic systems: Outdated septic systems have been replaced with more advanced and environmentally friendly systems, such as aerobic treatment units.
14. Non-permeable vapor barriers: Traditional vapor barriers didn't allow proper moisture transfer, leading to moisture issues. Permeable vapor barriers are now used for better ventilation.
15. Traditional post-and-beam construction: Traditional heavy timber post-and-beam construction has been replaced by lighter and more versatile engineered wood products.
These examples represent just a selection of the many obsolete home building practices that have been abandoned in favor of more improved and advanced methods over time. I do believe that the practice of pre-sloped mortar beds are just one more improvement over past practices.
While I agree a lot of modern practices are improvements ( asbestos NOT one of them, it was health reasons and not for practical reasons, as asbestos MADE things/products better ), your point you tried to make actually makes my point. From turn of last century drain systems for showers transitioned to "better" by introducing weep holes in drains which were used for 4-5 decades at least. whereas the IMPROVED shower system negates the weep hole system alltogether by implementing a sealed system, as I've done from at least 5 years ago with a liquid topical membrane & silicone at drain neck.....the so called divot system others adopted, or now with a product ( FLOEFEX DRAIN ) and sheet membrane. All 3 in my opinion work dependent on who installs, and all 3 do away with a weep hole mentality which is now antiquated anyway, which is YOUR point, out with old & in with new/improved.
That being said you only have to answer to you, I must answer to a customer base should I fail, and I've had no failures in 24 years.
@@StarrTile No, I'm accountable to a higher power: My wife, my children and my guests that may use this shower.
Your opinions are just that, opinions based on anecdotal empirical evidence you've gathered leading to your own conclusions, nothing more. You are an installer that chooses not to follow what's become an industry standard practice. In that respect you SHOULD be responsible to your customers.
Industry "best" practice is this:
"In a stall shower, the plumbing code requires the floor to be sloped one quarter (1/4) of an inch per foot in order to carry the water effectively to the drain. This slope, according to the TCNA Handbook is called “sloped fill” or commonly known as the pre-slope. This sloped material is installed under the pan liner (waterproofing membrane)."
The industry best practice (TCNA) for installing a shower bed with a sand/mortar mix is to use a pre-slope. This practice has been widely adopted and recommended by industry experts, tile manufacturers, and building codes for several reasons:
1. **Water Management:** A pre-slope ensures proper water drainage towards the shower drain, minimizing the risk of water pooling and potential leaks. This is especially important in showers where water exposure is frequent.
2. **Waterproofing Enhancement:** While modern waterproofing materials are effective, adding a pre-slope provides an additional layer of protection against water damage. It helps prevent any water that may penetrate through the tile and grout from reaching vulnerable areas, such as the shower pan or the subfloor.
3. **Long-Term Durability:** A properly installed pre-slope can contribute to the long-term durability and performance of the shower. It helps maintain the integrity of the shower system and reduces the likelihood of water-related issues, such as mold growth and deterioration.
4. **Compliance with Building Codes:** In many regions, building codes require the use of a pre-slope in shower installations to meet specific performance standards and prevent water damage.
That being said, it's essential to keep in mind that industry practices and recommendations may evolve over time.
I too am guilty of selectively deviating from industry practices sometimes as with the trend in faucets whereby they have limiting devices to prevent scalding. I'm 72 years old and in my lifetime never have had to rely on such devices to 'protect me from myself'.... I remove them from the faucets when installing them.
whats the big deal? seems to show it doesn,t matter either way. The mix used has barely seen any cement so not surprisingly crumbles sometimes and is very porous
I did my tub/shower conversion about 2 years ago. I live in a 40 year old double wide. I knew I was not going to use any tile because it is so expensive that I could never recover the cost. So I planned on just a bare cement type of floor pan. The drain was forced into the right rear corner because of the structure underneath. The bath tub was 54" wide. So with the long drain path I did a pre-slope for added measure. I concluded it would not hurt and might actually help. Since there was to be no tile, the pan would be saturated regularly. The cement would deteriorate over time. So the better the drain the longer it should last. Then I ran across a product that is used to seal concrete driveways and sidewalks. I put that on it and now the water just beads up like on wax. Like putting RedGard on top of it except it is clear. Only time will tell, but will probably last longer than the double wide does.
That sounds like a great plan, and I'm glad it's working so far !
Absolutely fascinating video, superb you proved your method is 100% the right way to do pan installations. As a plumber myself it amazes me you guys don't use ceramic shower trays , much easier , thanks again for taking the time to post the video , your a quality tradesmen👍
The shower pan liner be it CPE or PVC will not last forever if water is sitting on it. Just like everything else overtime it will deteriorate and eventually fail.
However for every shower pan liner you put in without a pre slope it will fail in probably 200 years. With a pre sloped the shower pan liner will fail and 350 years. In other words, you will be long dead, as well as the original owners, and there will be nobody to sue when the pan liner fails, and pull more importantly when the building is resold with the warranty as is.
With the building industry today, buildings don't last that long and neither do bathroom since they are remodeled every 15 years and rarely will a bathroom make it 30 years.
This is why in my state of Michigan they eliminated the pre slope in the building codes because it is just an extra expense that's a needless to the homeowner.
Jeff D
Living in a condo complex on the second floor?,
I demoed a 60 year-old shower because I was afraid the shower pan had failed.
No cracks in the tile, leaks onto the downstairs neighbor, or anything like that just OCD fear of liability claim.
Absolutely nothing was wrong with it. Even the membrane was in pristine shape!.
Chicken-wire tile too by the way....uuuughhhhhh!.
A pebble would have to be a perfect sphere for it to clog a weep hole. Also dont use pebble that are small enough to get stuck in a weep hole.
Bob why do you redguard your whole sand and cement bed in other videos if your no preslope is the way to go. Looks like the weight of the sand and cement made the center lower somewhat giving you a preslope
I started waterproofing the entirety of my for a couple of years ago, that's why the whole notion of a pre slope is a moot issue, but Isaac had challenged me after he did his video so I took him up on it
@@StarrTile Exactly. This is a non issue if you just waterproof the mud bed. Common sense solution when the issue is getting water into the mud bed.
Great videos
This is awesome! Thank God I don't have to do a preslope...
May Take 12 minutes without slope maybe with slope take 6 minutes byw u are a great tile master I like see a nice work done bcz i know isn't easy task to complete without years and years on real work field I know what's I talking about bcz I'm a plumber after 25 years I still learning from other trademan 👍
I am not a tiler, but a slope makes more logical sense than a flat surface for directing water once it gets to the bottom.
Now the debate perhaps should be how much pitch. Is it .25 inches per foot or .5" based on how much faster the water drained once you went from 1/4 inch to 1/2.
Again not a tiler but when you mention using common sense/logic, you were speaking my language. Lol
Anyway awesome video.
As a standard plumbing code a quarter inch slope per foot is great because you have air/gravity working on the water, in an encapsulated area as you have with a mortar bed gravity is proceeded by wicking action and therefore your pan will be moist all the time regardless of any type of slope... but yes, a quarter inch per foot is what they call for, having said that everybody waterproofs the pan surface now so the whole pre-slope notion is antiquated.
@StarrTile Thank you for responding so quickly. I have watched a few of your videos and will now watch a few more to understand better the differences between your preferred method and TileCoach's.
I am looking to redo my own 4x3 shower which currently is on plywood with fiberglass pan and surrounds...
Any specific videos you can point me to would be helpful.
Cheers.
@@PastorAngelV
ruclips.net/video/5Gp-PgGYi64/видео.html
@StarrTile Thank you Sir, appreciate you?
I'm with you Bob !!!
Convinced me to go with some type of one piece shower floor - there’s Darcy’s Law, but Jurin’s Law ultimately wins via time and invisible defects.
Great Video and experimental proof, capillary action works!!! If that slab had been allowed to sit a month, like in an unrented apt, then it would have been bone dry whether the pan was level or not, capillary action trumps gravity!!!
Good Job! And yes, a shower pan that is old will have a lot of smelly stuff in it due to all the tiny dead skin cells and stuff, unless it's Red Gard'd!!!
Awesome video. Never did use peples around the drain. If water can get through the mortar to the painliner, I always thought it could get through the mortar in the weep holes. Prepitches are required by code here in Florida.
I do not use pebbles and use the plastic disk too. So I agree on the point. Although the issue with no preslope is to help water from pooling in the corners of the pan or the low spots. This video shows those low spots. Now the issue is mildew growth. I have seen it on ALL non-presloped pans. All the corners will have mildew growth from under the tile and can never be removed. All of the presloped pans do not have this issue.
Sure not using a preslope is easy, drains 90% of the water, but mildew growth in the grout lines is a major issue with this.
This video is a prefect example of water pooling in the pan. All the water would have drained if there was a preslope going all the way to the drain. The mistake is Starr just props up the edge of the pan not the whole pan.
seems to me "capillary might be better than gravity" BUT "capillary PLUS gravity" might be even better ..... I suppose no slope is not a critical flaw , they've been done like that forever , but maybe a little slope is just a little added extra benefit , not critical , but just a bit better , can't hurt .... That's my take on it
I loved seeing this to show the silliness of pebbles. It makes the permeability of mortar bed perfectly clear!
Okay, most interesting demonstration but the comment at the end is most relevant to me: "most tilers are...waterproofing their pan surface". That's what I'm struggling with. Someone please explain why anyone would build a shower pan out of a porous, unsealed material. You wouldn't install a toilet or a sink that's porous to water.
I am **totally NOT** sold on the premise that no pre slope in needed. Goes against everything I was ever taught by numerous installers/contractors. Gravity is what governs where water travels. Period. Yes capillary action exists but gravity still directs it. Drive or hike up any river or creek bed and watch nature work. Then paddle down it in a kayak if you have the skills. I agree with much of Starr Tile's logic and his demonstration, and all... But will always include a pre slope element to avoid allowing any possibility of water finding a spot to pool up and hang out. These days with paint on waterproof membranes I fully coat the top surface of my shower pans (Hydroban), usually 3 coats to be sure to get the required thickness. Also I coat the subfloor and the pre slope. I end up with a layer cake which I believe strengthens the entire pan and keeps water from the mortar bed. So after it penetrates grout/thinset layers it hits membrane and is inclined to follow slope to drain. I agree it percolates through daypack just fine through weep holes and other egress points of drain assembly. But I see no reason to exclude slope from the equation based on this video.
If preslope doesn't at the very minimum aid in drainage of the water that reaches the pan, explain all the showers I've had to rip out that had no preslope and we're absolutely full of standing water? Not too say that a hack couldn't screw up a preslope style pan system. I for the record have never remove a leaking shower with a preslope. When using mud i do preslope unless I'm waterproofing from the top.
You've just agreed with StarrTile's argument. He always waterproofs the mud bed. That's why he says a preslope is not necessary.
Love all the information very worthy. Would love to know is it normal that there is still water to be sitting on the actual drain?😂
If your floor is perfectly flat you do not need a preslope. This video is like a preslope setting of 0. A perfectly flat base makes it very easy for the water to wick it's way to the drain. Also, since your liner is a few mm thick, when it meets the walls it slopes upwards (there is a curve at the 90 degree) so technically there no negative slope or opposing slope in the pan. it's basically a bucket on a flat floor. If you install the liner nice and tight and your floor is flat there is no reason why it shouldn't drain. You need to preslope when your base is not flat, like the concrete in your basement is built poorly, or when the carpenters build the floor poorly. Or even if there is a very small slope in the overall floor of the washroom. if some of your shower base slopes away from your drain or if the entire floor drains to one side, then you are relying on the wicking power to pull the water up the opposing slope and then into the drain. There will be a point where the wicking power is not able to pull the water up the opposing slope. the wick power is directly related to the size of the pour spaces. the smaller the pores the stronger the water can pull. Wicking is due to the water molecule being di polar. when the negatively charged oxygen in the water molecules come into contact with other negatively charged oxygen elements in the other water molecules they push away from each other. Same goes for the 2 hydrogen elements because ++ push away from each other and same goes for --. when they hit other H's in other molecules they push away from each other. You don't see anything happening at a depth but on the surface of water you can see the effect of the collisions because they are not balanced by other molecules. So the top layer of water doesn't have water on top of it to balance out the o's and the H's pushing off each other so it makes skin like behavior. insects walk on water because of this. A miniscus forms at the edge of your glass because of this. Unbalanced water molecule collisions are pushing the water up the the side of your glass. This happens at every interface between water and air. there's an unbalanced effect.
When you dip a napkin in a glass of water you will see the water rise up the napkin because of the energy that the collisions are creating at the air/water interface. The smaller the pores the higher it will rise because the energy has to carry less weight. larger pore spaces means a larger amount of water needed to fill the pore which is heavier. So the size of the poor spaces in the dry pack can only pull water up a certain amount. If your base is ever poorly sloped then there's a chance that the wick can't drain the drypack. This action also works horizontally, if the water falls into the drain then the pore spaces next to the drain have air in them and the pores adjacent to those pores are full of water so it pushes in that direction.
So a flat surface like this experiment, a 0 slope will work. if you are ever uncertain, just preslope it and don't risk it.
great video.
I still believe the preslope will allow more water to find its way out , however i am going to waterproof my shower beds to reduce the amount of water that makes it into the shower base, and hopefully reduce mold build up under the floor tile
awesome video.... so I saw a video of you applying Red Guard... is this where I would apply it ? onto the mortar ?and then after 3 layers.... next is thinset for tiles ?
Yes
@@StarrTile would also like to ask you about the type of grout to use on floor tile in the shower floor. should we be using epoxy grout or something else ? TIA
I use Prism by default on every job I do the last few years
I know this vid is 2 years old, but it reminded me of an experiment back in middle school. If you take a stalk of celery and put it in food-colored water, the stalk will suck up the liquid far above the lowest point of the container. It’s an easier visualization of capillary action. So no, water doesn’t always go to the lowest place.
Not a very good test. The shims only tilt the table in one direction. They don't provide a slope towards the drain. This means that the water not sloped towards the drain is providing resistance to the water directly upstream of the drain. Not to mention the bubbled-up liner that results in water having to go over hills to get to the drain.
terribly flawed experiments, basically rigged the first 1, the 2nd was set up already containing the problem to start with as if it was a consistent variable. your argument is completely missing the point. No offense but youre not even asking the right questions bud. Maybe this is for views or IDK........... IF YOUR BED IS COMPLETELY SATURATED AND THERE IS RESIDUAL WATER IN YOUR PAN THEN IT"S ALREADY FAILED AND the problem there is you dont see why or how thats a problem........ IT"S NOT ROCKET SCIENCE GUYS. People spend too much $$$ on shit for amateurs to gamble with and risk doubling/tripling the cost just bc a dudes argument for how shit may not always run downhill is enough to talk himself out of a half days work and thats taking your sweet precious time.
SO MR STARR. are you now using redguard over the entire dry pack? i know at one time you were just doing like 6 inches around perimeter. what i dont get is the words " mold sandwich" i see this phrase every time someone asks can you use a liquid membrane over a water in water out system, well why isnt this mold sammy happening in a schluter type system? i guess the only difference would be that in a schluter system the water under tile is making its way to the drain but afaik thats not happening as the water just evaporates, but if it did then just dont put liquid membrane in the general vacinity of the drain in a liner system and that water would also drop down to weep holes...
It’s not just capillary action, it’s hydronic pressure, the pre slope is just for incase but with that said, water won’t wick to the pan just because. Experiment is flawed. It’s not the end all of you don’t preslope but over time you can end up having an issue a extra 30 minutes can 100% prevent. The mortar bed is porous and if it is to get completely saturated and make it to the rubber liner then there’s a good chance it’s not goi g to come all the way back up thru it or wick it’s way to the drain
Hi this is nice testing but it is not in real life testing. First you supposed to build the regular size shower not 3 by 3 feet shower. If is smaller water can penetrate much faster and easier because the distance to the drain is shorter.
I think it is depends where you have the drain. If you have linear drain 4 inch from the wall you probably need to do that pre slope because water can set across the drain wall if you don’t have the pre slope. This is very good question you need to have it pre slope or not.
Pre-slop or not pre-slop? I am remodeling my own bathroom and this question got me puzzled all over. Could not get to point why should I do this sandwich, so went to no pre-slop. But very pleased to find discussion here on this topic, that helped me finally to get to the point why many care for pre-slop. 1: Let water to get out from low spots in top layer of mortar. 2. To avoid liability.
Thanks so much for this clarification! But I am not about to redo none slop pan that I already did. Just curious, I painted the the top layer with waterproofed paint, what difference it might make? Also I painted under the liner all the sides of the shower to prevent from tiny ants coming because I saw them under old pan when removing it. Those beasts are the nuisance in FL and they get to any place in the house where they have enough moisture. The shower is one one of them and I wonder that no one is offering the way to fight those creatures.
StarrTile, The evidence is on you to prove that a pre-slope shower pan doesn't improve overall function. You've just shown us how a shower pan works with no pre-slope.
Evidence that a preslope works is on Issac's video that I linked..Evidence it doesn't help is here... I am not the Trier of fact I simply present the evidence
Preslope is just extra insurance
Awesome. I wanna do a tile shower was just going to get an acrylic pan because a pre slope was too intimidating. Thanks for the info brudda
The man I apprenticed to explained to tee the same that you explained. His 40yrs experience and my 20yrs never used or had issues with a preslope.
It seems the bubbles in your pan liner are given false readings
I agree with you and have watched a lot of you videos thank you for all the great info. You helped me so much building my first ever shower
this is the first time ive heard of people putting rocks and pebbles to stop the weep holes from getting clogged. Never heard of it, its not in the handbook. Wonder who thought of that.
It's a fairly common practice in Florida...well, used to be.
Now, Florida Building Code mandates that ALL shower pans MUST BE pre-pitched before installing your pan liner. They even have a pre-pitch inspection you have to call in before placing your liner. It's ridiculous! It wastes a whole day before you can continue with the remodel
I don’t see how that would help unless you covered the whole bottom of the pan with a thin layer of gravel. If the water is going to wick through the mortar, it seems like it could wick through the mortar that blocks the weep holes.
@@MoneyManHolmes and that is the irony about people who say water will get into your pan material which is mortar mix but they dispute that it can get into your mortar mix through the weep holes, so freaking illogical
Just open the Oatey manual and it shows the pebbles and pre-slope. Not debating good or bad, just noting it’s in the docs. www.oatey.com/ASSETS/DOCUMENTS/ITEMS/EN/showerpanliner.pdf
We can all agree if you’re getting water into the pan liner you’ve already failed. Some are just gonna fail faster.
What am i missing? It seems if the water happen to break through liner, then it will just go through the preslope mortar as well and end up on the wood or slab. 🤔
I suggest we do comparison experiments for saturated pan with/without pre-slope to see if there is a difference in the amount of new water that replaces old water. First let's use water with certain concentration of ink to saturate both shower pan mud beds, then use clean water to 'wash' the mud beds to see if there is a difference in the color of water coming out of both mud beds...
That's a great idea and an experiment like that would be the only way to truly know if water is cycling.
Having said that it's a moot issue because everyone waterproof their pan surface now so no water gets in to begin with
@@StarrTile
What do people use to waterproof their pan surface? Redgard?
Yes, or Aqua defense or Hydro ban or 8 + 9 or Kerdi
Use preformed pans. Leak free, mold free, End of story.
Oatey makes a preslope to go under the rubber mat. Cost $75.
to my understanding, you said the soapy shower water deteriorates the sand-mortar mix. It deteriorates the cement components and leaves the sand behind. So anytime water gets into the mortar mix is bad? Is this correct? or is it ok for the mortar mix to get saturated? I realize that you use thin set around drain and you mention it helps the redguard waterproofing to adhere better. that was said in another video of yours. then you coat with redguard. This is to ensure that water never actually enters the mortar bed but it is there as a backup? This is my understanding of the video, am i understanding correctly? This is very helpful to me.
The backup is the pan liner. If installed correctly, it should also stop water getting into the mud bed.
Help me understand, the majority of the water drained from the top of the deck mud to the weep holes on top, yes? Very little is going to permeate the mud , especially because you rightly pre saturated it. It’s the path of least resistance. Heat moved from hot to cold, water moves from wet to dry. Only a small amount is going to move down through the mud . Once there the hydrostatic pressure is a weak force. Any “ trapped “ water will move to the driest place by capillary action. No pre slope needed.
So I made a video years ago called "pre slope explained".... probably still on my channel and it was kind of off the cuff type of video that I did because I was frustrated people pushing back on my theory. Fast forward to the last 3 or 4 years, everybody waterproofs the surface of the pan so the pre-slope idea and weep holes are as Antiquated as a phone booth.
Thanks for the test. Seems like there's a lot of debate on whether to pre slope. I'll stick with the recommendations of the American standard institute of ceramic tile as well as the tile institute of North America. I'm going to guess they collectively have more knowledge and experience then any one person. They recommended pre slope. Furthermore its also an insurance policy against potential litigation. It's going to be hard to argue against a recommendation from such Institutes which more often than not are basis for standard practices/code.
You are free to do whatever you like, code aside because there is no code where I'm at to do a pre slope, the reason I did the experiment is to prove it's irrelevant, if not for everyone else then at least to myself. And because entities recommend something isn't because they feel it's necessary, they do it to CYA against operator malfunction...same for the hot label on coffee cups. Legal process and litigation is the last thing I'm worried about, my showers are built 10times better than what I tore out, and those ppl selling products or recommend something will never go to bat for you regardless, they have no desire to defend *you*...lawyers will be sure to disseminate every step you failed at, not just this one. Having said all of that, it's a moot issue anyway since tile guys are waterproofing their pans now, so a preslope is irrelevant.
Bob, good demo, much appreciated. One question, could you waterproof the top of the mud to prevent water seepage through the mud base?
I have been doing that for the last three or four years now, so yes, the shower should be functional with no tile on it
Thank you Bob, I’m converting my tub to shower on concrete slab, and will apply a few coats of waterproofing on the mud base before laying the tiles.
Keep these videos coming.
I think on a larger shower base you would not get the same result.
Does the mortar adhere to the rubber underlayment like glue after it dries? Or after the mortar dries and shrinks a little, would it be possible for some space or gaps to occur which then the pre slope would always be aiming that residual water back into the drain?
Although I would like to answer your question we are all doing a sealed system which now makes a pre Slope a non issue and antiquated
Nice video but I'm still doing a pre-slope. Your demonstration is defined by there always being some amount of water in the pan. I'd like to have my pan become as dry as possible much like the way a tub or sink drains until it is dry. Also, I get the use of "pebbles" but never felt the need-so at least you verified that especially since most drains are centrally located and will see the most force from people standing on or close to it. (pebbles making for a weak spot).
Honestly I have stopped talking about pre slopes going back probably 5 years....the kool-aid is too strong. But I will say this, with wicking action your pan will never ever be dry...pebbles can clog holes easier than mortar because pebbles are dense. And as you mentioned cause a weak spot. Intuitively it makes no sense since 1/4" per foot is a plumbing code for gravity fed water in a sewer line, not encapsulated with 200pounds of mortar. So critical thinking is necessary to overcome the myth fed theory.
Having said all that nobody does the pre-slope anymore because we have transitioned to a sealed system in the last 3-4 years, although I started creating my own sealed system about 7 or 8 years ago and it is Bulletproof. This leaves preslopes as irrelevant as a phone booth.
Stuff weep holes with bread water will dissolve
I never used a pre slupe before shower pan and no problem at all