I have been building Encapsulations from Knoxville Tn to Kingsport Tn for 15 years. Refreshing to hear a completely accurate report. You are truly better off with nothing, rather than fiberglass batts. The rim joists is where 20% of all heating and air conditioning loss comes from because , like he said, nothing is there but a 2 x 10. In almost 1/3 of all homes, you can see the sunlight in and around the band joists (same as rim joists) because the 2" board is too hard to cut (and there's a lot of cuts) , we use 1" Owens Corning board. We pop a 1-1/4" roofing nail in the middle of the board to hold it in place while we foam around it. It's time consuming, but if you pre-cut the boards at the shop, it goes faster. There are lots of non-standard spots and many places where pipes or wires go through. It's best to get accurate measurements for those, and cut them at the shop and write on the PM with a marker. Last two hints. 1) Leave a space above the foam board to shoot the foam into. Foam doesn't have anything to sit on if you don't, and if you're going to drive a roofing nail (a box at Lowes is $3.88) you can't get a hammer into that area. Poke the nail into the foam board first and use something as an extension to hit with a hammer. We have a one inch round lead pipe that's 10 inches long. Very last hint. Major cities Home Depot and Lowes will rent a Fogger and both sell Concrobium Mold Control ($37 gallon, or $9.50 for 16 oz spray bottle) It kills every mold spore instantly and no mold can grow on that lumber again.....EVER !!!! I can't say enough about this product. Whole families were seeing the allergy doctor until we fogged their crawlspace . Angie Hicks of Angie's list made a video BLASTING allergy doctors for NOT telling their clients to atleast have their crawl space looked at. They must have made her take it down. Lastly, an air quality specialist costs four hundred and fifty dollars, you spend seventy percent of your life inside your home breathing God knows what.... these dudes are good and they have the instruments..good luck with your home,
fetty guapo Quite Welcome. I've seen everything from a 34 year old couple with three kids have to abandon their home, doctors orders. And I've seen Radon at a level 12 kill a 40 year old woman (lawyer) and I THINK that bat guano killed another gentleman. Tin roofs are great, but if the contractor doesn't put this fiber-like material under the ridge cap, and bats decide to make it a satellite home? Well, this fella ended up with them in the walls and everything. Histoplasmosis kills people and that's what he had. Almost every tin roof contractor puts the stuff, but when they don't, man it's like Russia roulette. Should be inspected. Darn shame to see somebody house harm them, or worse. It troubles me.
Troy Baker Good question : in Tenn. you can't take to board to the tops of the walls, as shown in this video. It must stop 4 inches below the tops of the walls. That's supposed to be so that termite inspectors can see mud tunnels. But I was a termite inspector too for nine years, and they prefer to come up through the dark, damp hollow block and eat from the inside out on the floor sill. TN code says to use R10 , or 2 inches of foam board in the band joists. We don't do that for just the reason you described. We use only one once. That gives the termite inspector room to jam a screwdriver into the floor sill to see if it's being attacked. By the way, Termites were totally defeated with the advent of Termidor SC in 2004. It's so dafe, homeowners can get it online. I do not understand anybody having Termites these days. Treat you own home every ten years.
UnderStructureRepair Thanks for the info in your reply. Do you know of a good reference for a homeowner applying Termidor SC? I'll continue looking at the product website but often professionals and DIYers have good tips on product use. Finally, thanks to NWOHI for the original video!
Thanks for the visuals. Seeing quite a few bad takes here in the comments. Simple summary: the fiberglass does not stop air movement. Moist air from inside the crawl space moves through the fiber glass bat and condenses on the cold rim joist. It's not likely to dry, and that's where the wet and black staining comes from. The solution here is to remove the fiberglass, cut and cobble rigid foam and seal the perimeter of the rigid foam blocks with spray foam. Care should be taken to choose the right rigid foam thickness for the climate zone to ensure the inside face of the foam remains above the due point. There are simple tables to find the proper thickness for your climate zone. This topic has been covered repeatedly on the green building advisor website and fine home building podcasts.
@Fred Wills yes, and this is an important point. Exposed foam is to be covered with some sort of flame retarder. The easiest solution here is to get the foam with foil face on one side that is fire rated. It's only marginally more expensive than the standard foam and it's still readily available at the big box stores (at least here in the north east). Plywood, or drywall are also acceptable in most regions and versions of the code, but who wants to do that?
Thanks! I was specifically referring to DOW Thermax which is foil faced and Class A Fire rated and can be left exposed. @@teamdada2194 If you have a good source that says otherwise please share I’d love to read it. www.dupont.com/content/dam/dupont/amer/us/en/performance-building-solutions/public/documents/en/thermax-sheathing-pis-43-D100094-enNA.pdf
The problem is not with the fiberglass bat, but with improper installation and the lack of vapor barrier. If you're using fiberglass bat it should be cut to fit the space snuggly and a vapor barrier installed and sealed with acoustic sealant. No more air transfer.
In cases like this. With a good fitting batt, a person can also buy a closed cell spray kit and cover the insulation batt. Both adding insulation and proper Vapor barrier. Costs more though
When I insulate a band joist I start by caulking to stop the air infiltration as much as possible. I caulk the seam where the sill plate sits on the foundation, where the band joist sits on the sill plate, where the floor sits on the band joist, also there the floor joists hit the band joist (the nail holes leak). When you pull the pink insulation out you can see stains in it from all the air leaks. I used mineral wool the last time I did this because if a termite inspection is needed, they can move it out of the way without damage.
Spray foam or Styrofoam (blue board) to insulate the rim joist cavities (RJC), not a chance! Maybe you can get away with that Ohio or in the North but that’s a huge mistake in the mid-Atlantic and southern states where a risk of termites exist. Stay away from the blue board, use something of a better quality such as Hunter brand for the walls (it has dual sided fiber reinforced vapor barrier). Take the Hunter board up to within 2” of the top of the block/brick/cast wall and leave the 2” gap for a termite reveal. Next use RockWool insulation for the RJC to limit heat transfer, this allows for easy removal for termite inspection and it doesn’t absorb moisture as fiberglass will. You want to take it to to the next level then insulate the ground 24” horizontally in from the wall around the full exterior perimeter of the wall. Cover the entire ground with a class 1 vapor retarder (20mil) with 6” overlap at the seams and tapped with 4” vapor tape. Install an appropriate sized dehumidifier that will remove around 80-100 pints of moisture per day on a dedicated GFCI outlet. Upgrade your access door to seal tight with weatherstripping and insulated on the inside. Biggest take away for anyone reading this is to limit the use of spray foam in a crawlspace. I’ve seen spray foamed 6x6 beams with 80% rot because of trapped moisture. I’ve seen rim joists and joist tails completely decimated by termites and you could only tell by probing the wood with a wood probe (could actually stick a pencil through the lumber). Save the spray foam for inside the structure. Moisture in the RJC is not from “air transfer” as suggested, it’s a dew point issue. The exterior framing, if constructed properly, should have house warp with taped seams such as Tyvek for a vapor barrier over all exterior sheathing.
Hmm query what about snow areas seen most of cabins up big bear floors are insulated with insulation held in place with wire loops made and bent for that pourpose
We have rim joist batts in our 35 year old home and do not have any problems with moisture, mold, or other. The outside of the rim joist and side walls is covered with 1 inch Tuff-R foam, then Tyvek sheeting, then 1/2 inch t-111 siding. Works for us.
It's probably best to do inside and out if you use 1/2 inch foam on exterior But if you go any thicker on the outside then you're right inside is not necessary.
Makes sense. If the inside surface of the rim does not get too cold then it will not drop below the dew point, hence no condensation. How wet/dry is your basement/crawlspace?
The issue with bat insulation in rim joist is above that insulation is living space and. It will keep a cold floor 10 inches or so from the wall. As it's technically part of the outside not inside heated space now.
We have no exterior foam, but I have a New York home and also batts. No problems at all. I’m positive if I remove one now I’d see no issues behind it. I do run a dehumidifier 365 days/year keeping basement at 50-55
Use Rockwool type bats and cut them to fit very very snug. Do around R25 to R30. You need the joists to breathe a little or trapped moisture will mold the joists. If the exterior is not Tyvek'd or sealed you will always have moist air intrusion.
I live in a cold climate and agree your summation is correct. Here we also need a poly (Visqueen) barrier anywhere low density foam or batting is used. We do not need or want to leave a strip of sill plate exposed for termite check because no termites here. Guess u don’t hv them either. I like your commment about being able to remove foamed-in sheet foam versus urethane sprayed foam. Good point. Cutting and can foaming is very labor intensive. You show a good example of how a good job looks. In a cold climate it would take 4 layers of 2 inch rigid foam to make me happy, with each layer can foamed. So I would bring in the urethane foam truck for almost all bays. I know u pointed out the batting moisture problem likely caused from vapor. I think u also mentioned the need to air seal the rim joists. In a multi story house there is a big stack effect with any air path from the basement. The man who built our house urethaned some sill bays, but in some bays he meticulously cut rigid foam blocks. Very neat precise cutting. Must hv had a hot wire. He did not can foam the cuts. During a remodel of ours we found his work. His hand custom cutting with no can foam was a BIG mistake. Terribly drafty. Found dead flys and yellow jacket small nests in locations one would swear a bug couldn’t get to. Harmless enough but the drafty issue I am sure stole much of the R value of his work. Thx for your vid. Good commentary from you.
The contractor used fiberglass in my home's rim joists and I found mildew-ish growths in some, plus the Northeast corner in the master bedroom would form ice on the wall. I tore out all the fiberglass and paid to have proper foam in place. Cost for my 1800 square foot home was $750.
Exactly. Also 1 1/2” strip to fill space below joists up to sill plate especially if it’s a block foundation. And zip tape the seams. Also at that point you can put the fiberglass back in.
When we finished our basement, I used batts in the rim joist, then cut plastic to fit over the batts. Embedded the edge of the plastic in acoustical sealant then even added staples to hold it all in place. About 5 years later we noticed one of the basement rooms was abnormally cool. Started investigating and removed from suspended ceiling tiles in the basement and noticed that the acoustical sealant which was supposed to remain flexible had hardened and let loose in some areas leaving gaps between the plastic and floor joists. Pulled the plastic and batt insulation away to find a 1” thick layer of ice on the rim joist. 😕. Ended up taking the entire ceiling down near the rim joist and pulling plastic and insulating everywhere from the rim joists luckily only found a few more problem spots. Ended up cleaning up what mold had appeared, dried everything out then spray foamed the whole perimeter. Should have just spent the money on spray foam in the first place, way quicker install and complete air tight.
The approved way to airseal an open space is 2mil plastic sheeting (white flame resistant type if exposed) taped at all edges with 3” white tape. We use this in metal buildings all the time. Unfortunately using this for rim joists is difficult so I prefer 1” foam on the OUTSIDE of the rim joist but this is impossible on most retrofits.
@@MrChadder007 closed cell foam is a good insulator but it will crack over time losing all air sealing qualities. It is not acceptable as an air barrier that has to be inspected. Most rim joist insulation is not inspected, but might as well do it right I figure…
Cold-climate-liver (love it). Stack effect is real (and powerful). Vapour barrier is difficult to install as a defence at the rim joist (ten tubes of acoustic sealant later). I'm still assessing whether well-installed spray-foam will work better. As the house flexes from warm-humid to cold-dry I'm fairly certain cracks have been opening that I cannot see. Part of the problem is we over-"air condition" in hot weather and over-heat in the cold. We've only had a few decades to see what happens. Also...properly installed exterior insulation if you are doing a new-build (but investigate HVAC air exchange). In most districts these things are code where I live. If I were able to build a new house, I'm interested in insulated concrete forms...but you need a competent contractor. I'd also be happy with a tiny cabin and a wood stove, windows that open in the summer. Where I live it takes a century of shameful neglect before those things decay. I am fond of modern cooking/laundry appliances however..so get your electrical together..
The problem is high RH in an area with leakage, not batt insulation. Batt gets a bad rap because it’s in the right place at the wrong time (when air leaks and temp differentials are greatest. Too much humidity inside will result in condensation anywhere there is air leakage. Windows are no different. The rim leaks air just as any other area of a wood framed home. If you’re going to put any type of insulation in a joist pocket you need to make sure you first seal it so the batts can do their duty via thermal barrier. Batts are not sealers or vapor barriers, and when installed in a spot where it’s surrounding environment has high humidity with leakage, wahla you have condensed.
Exactly. I live in WNY and just pulled my non-vapor barrier rim joist fiberglass that was installed in the 70s to inspect things as I remodeled my unheated basement. The joists are perfect, no signs of dampness, no rot, no mold. Humidity drops like a rock in winter where I live. If your basement is occupied, then you need to seal the rims with a vapor barrier, just like the concrete walls should be. If not, then leaving them unsealed is fine. I run a dehumidifier set to auto mode all year... it keeps the basement humidity to under 45% or less.
air flow is good, that is not your problem. your problem is that you do not have vapor barrier on the inside of your insulation like you do everywhere else in the house, the air moves right through as warm, moist, air and then condensates into actual moisture once it leaves the zone of the heated house inside of the insulation. you should cut a piece of poly for every joist spacing and acoustical seal it into place. I seriously cant believe you are an inspector. Styro is a good idea but I would still do batt insulation first so that the wood can breath instead of placing styro foam directly to the wood, that will lock moisture up against the wood with no way to escape.
I have an older house with a basement that has no sill plate. The wood sits directly on top of the blocks. Three sides are below grade and one is exposed to the elements. How do I insulate for that?
Our house had the fiberglass batt insulation at rim joist in our basement when we moved it. The house is 40 years old. The wood at the rim rotted and we got mice and wasps making nests in that insulation, entering from the rotted outside overhang.
you need vapor barrier. the wood is the coldest in winter since the outside of the house is way below 55F which is the temperature of the ground inside. the moisture will condense on the cold wood surface. use plastic to block the moisture, then the fiberglass should work well.
Vapor barrier or facing on fiberglass ins. Will trap moisture against the rim board and will cause wood rot !! Either use fiberglass R19 unfazed or spray foam 3 in. Which is the best way .
@hugolafhugolaf The insulation you have is ancient and outmoded. The insulation in this video is modern and far superior. If you have the funds, an upgrade would work wonders. The difference will be night and day.
@@cquilty1Of course it is. It works though. My house, depsite dating back to 1970, is as energy efficient as any new home that is not built to super-stringent eco-criterias. And yes, I've had it tested. I was very surprised.
@@hugolafhugolaf A 1983 Geo Metro still works. But nowhere near as well as a brand new Honda Accord. The efficiency of insulation today compared with 1970 is vastly superior. Regardless of any eco pluses or otherwise.
@@hugolafhugolaf Ha! As already mentioned the difference would be night day. The square wheel is more useful/efficient than the insulation you have right now. Also, in the ensuing half a century plus since your insulation was installed, not only has insulation improved enormously, codes have changed and the R value requirements are far far higher But as long as you still enjoy driving that dented, oil burning, rusty old Geo Metro with springs coming up through the seats, that's the main thing:)
I have tried to explain this to people doing bad basement renovations. Run that foam board straight up in to each cavity to the plywood above, and spray foam around. Then you have even vapor transfer along the backside of the foam to the outside. Then your crawlspace or basement will stay fairly warm and dry compared to the outside air temp. In basements, you are essentially building a "bucket" with no leaks that your framing and finishes will sit inside, and you leave the outside area with the concrete and above grade wood to transfer moisture up and out. I recommend DMX 1 step for floor surface prep and then install tongue and groove wood sheathing over that. Then you will be giving yourself a little insurance when you have moisture events in your house.
I love your adding the comment about removing the glass batt rim insulation and installing the Extruded Polystyrene rigid insulation with the spray foam sealing. To put it mildly, “you have your shit together”. I’m a semi-retired professional roofing and waterproofing consultant with over 40 years of actual field experience.
Should mention whether this is an encapsulated crawlspace or a vented one, dirt floor or poured concrete. All factors to consider as moisture control is key in crawlspace. If encapsulated you will need some sort of method to control humidity (dehumidifier) and if it is a dirt floor then want to look at installing (minimum) 6mil VB and running it 6-10" up the wall (on the warm side of the rigid insulation then tuct tape all the seams - that way any moisture that builds behind the rigid foam will stay under the VB.
VAPOR BARRIER & TUCK TAPE One quick question...is the ground covered with a vapor barrier of some sort? Moisture and Argon gas will build up if the ground is not covered with some sort of vapor barrier. There is a 10 mil. heavy poly that is used under slabs, which can be used for this application. This will help to alleviate any ground moisture problems. Now if each rim joist gap is sealed with vapor barrier and tuck tape, or accoustic caulk / sealant, using fiberglass insulation is just fine. Any moisture within that crawl space will be stopped. But if you constantly have moisture coming up from the soil, the joists could eventually rot too. Vapor sealing the entire crawl space is what needs to happen.
Its not just the air transfer its the temperature difference causing condensation. Partially conditioned crawlspace with dehumidifier and blueboard, no fiberglass hydroscopic mold grower, use rock wool it breathes and is not hydroscopic and wont grow mold. Radiant barrier helps also. My crawlspace is at 65 degrees and 30 percent humidity. In house its 68 and 37 respectively.
In the northern climate the old timers would always say to not insulate basement walls from inside. The push of frozen earth on the concrete or worse block walls causes cracks even bulging. Insulation should be buried outside down at least 2.5ft . You can see after a snow that the outside perimeter ground around the bldg will be thawed this shows the heat loss but what is more expensive heat loss or hiring a foundation repair firm. Food for thought
This is a classic vapor barrier scenario, not a fiberglass specific issue. Lower cost solution is to use faced fiberglass cut to size, with the facing stapled and tucked as with any fiberglass install. The facing on fiberglass is generally around 1 perm. EPS offers nothing, you'd have to use XPS specifically (blue board as mentioned, Foamular, etc)
The question is where the damp come from. Is it from the outside or from inside. In general I think it is a problem when the inspector likes or dislikes solutions. They are either accordingly to code, or not.
Looks like a dirt floor in there so it would be important to direct the downspout water over 10 feet from the foundation, make all the difference in how dry your crawl space is.
So what if the carpenter who built the building in the first place put the vapor barrier on correctly on the outside? Or what if you spray from the edges and then used the batt insulation? I think it's wrong to blame the insulation for poor prep work. You've obviously never removed blue board and seen the mold and mildew that's behind it.
curious to what the impact is on this type of insulation on termite inspections? I encapsulated my crawlspace and have two inch foam boards against the cinder blocks. my termite inspector wants to see more wood to verify no termite infestation. just curious, I've seen other videos advocating spray foam adjacent to the joists.
In this instance nothing you have spoken to will eliminate the rim joist being a condensation point and thus in need of a way drying after condensation. I'm not sure I know how to deal with it. Joseph Lstiburek does, though.
There should be a vapor barrier on the outside if not it was built wrong which would prevent that happening. The problem is there is way to much moisture in the crawl space and the fiberglass is soaking it up. The crawl space is the problem not the fiberglass.
I saw somewhere that if you place the fiberglass batt into a kitchen catcher plastic bag and slash an X in the outside side. This is a fast way to add a vaper barrier like the upstairs walls.
Surely ventilate the crawl space to outside and insulate under the floor, with no ventilation from the house interior to crawl space. That way you will avoid warm moist air coming into contact with the cold rim joist.
Don't know if I solved the problem or made it worse as I've since moved from the house, in Ohio but when i moved in there was batted insulation at the rim joists, I removed it and placed each batt into a heavy plastic bag ,sealed it and replaced them. No loose insulation to shed, no dampness in the insulation and cleanly removable for inspection. Never saw (over 15 yrs.) wetness, insects or mold. Perhaps just lucky, perhaps a solution?
The problem is isn’t the bat insulation. The problem is moisture is getting in from the outside probably due to the lack of a proper vapor barrier and/or improper caulking on siding and trim. Look outside for the problem.
I see what you’re saying. If that was the case then the homeowner would probably be better off having no insulation at all there. Because at the beginning of the video he does talk about airflow which would mitigate condensation due to temperature gradient from outside to inside.
Tim Coleman I own a old farm house, and the way I did it was too insulate the all the floor joists. This keeps the heat out of the crawl space . And keeps the floors warm. Then the crawl space is vented well. This protects the home from moisture and keeps the crawl space nice and dry. If there is any pipes in the crawl space they too are wrapped very well with insulation. A little more work and money , but worth it. I have seen in some homes like mine where people did the same thing but also used plastic on the ground to hold off moisture. I think this is only needed if there are high water tables or low air flow do to trees and such.
tgmforum tgmforum because the crawl space is the same temp as the outside temp. There’s no condensation anywhere. You can also run plumbing between the floor and the insulation if your joist allow it. I used wrapped insulation and stapled it to the end of joist leaving a air space between floor and insulation.
Im a waterproofer, 33. Years. Dealing with this, listen and listen good, the only way to control. Humidity in. Your. Crawl is 3dehumidifier, only way, vents don’t help, foams help with air intrusion , but cant. Control. Two. Different air. Temps. An$ that is what causes. All. The. Fuss,...
@@dwalto1977 absolutely wrong thing to do with fibreglass batts. Look into how fibreglass batts actually work. The plastic negates any benefit to the batts. Not trying to be a smart ass. Rigid foam board is perfect in conjunction with expansion foam.Just put the insulation batts vertically after the rigid (room side). Because there is no air infiltration through the rigid insulation you will have no problems. Of course a vapour barrier on the warm side- done.
Missed the mark. The major issue is a lack of a vapor barrier. If this crawl space is not heated/conditioned air, then we should be seeing vents in addition to good insulation and vapor barrier. This space has insulation on the foundation, so maybe it is heated. In this case, the vapor barrier belongs on the outside of the rim joist.
I live in Idaho and that is not how we do crawlers. Air vents every 6-8 feet and R38 in the bays 6 mil on the ground. You get no mold unless standing water but that is a different problem. The floors stay warmer in the home. Condensation happens when cold meets warm with no air flow. so please show me the code on that one. It is a different zone than I know.
Joisting on top of foundations walls like that is a bad idea in general. Even if you put rigid in there and make it air tight. That rim board is still going to be cold on the outside and hot on the inside and create condensation. Same thing will happen with spray foam. It just makes it all less visible.
Yes but sorry to say. "Right" isnt sealing the condensation into that wood. The moisture content in that 2x10 rim board should be pretty much 0 before you seal that rigid insulation in there. If it was me doing that I'd be using 6" of ISO minimum so that rim board doesnt get cold enough to sweat and create moisture and condensation again. Even with 2" rigid on that concrete wall it's still considered a "cold room". In Vancouver B.C it is anyway
@J Wil for the most part we bolt on a ledger to the concrete and hang joists off that. For the most part joists only bear on the foundation when they cantilever beyond foundation. Things are different everywhere though. It's a very wet and humid climate here
So where you pulled that insulation off and saw mold on that wood...how do you now correct that? Kill mold and put another piece of wood over then spray foam?
Use a mold solution...I like: www.rmrsolutions.com/collections/diy-mold-removing-products?keyword=rmr%20solutions&gclid=CjwKCAjw38SoBhB6EiwA8EQVLs5vSryMqrAxhzBNWFqXFxYuOYgkt3A3MOeXAt4i-MGz8twCrGfzThoCSvMQAvD_BwE Then insulate with foamboard and shoot a bead of spray foam around the perimeter of the foamboard to cover the gaps.
I've read just about every comment listed for this video. I've determined that there is NO WAY of learning how to do this correctly by watching these videos. People in the comments have listed about 2 dozen different ways that they think it should be done. You would think mankind would've more fully evolved on this topic by now. It can't possibly be this controversial! Oh well, I'll do it my own way.
Thanks for watching. Everything, and I mean everything, is debatable, in this day and age with the internet :) You can find support and controversy for anything you choose to. My experience is from things I see day in and day out. Did you read the blog I wrote in the comments?
I agree. I sat here searching for the correct way to insulate the rim joists. Two hrs later , still sitting here searching. Its because there are too many know it alls! Just getting more frustrated. lol. Besides actual spray foam, there seems to be no correct way. My thought was to put 1" polystyrene, sealed around all edges, against the rim joist, and then putting in Roxul. It would fit snugly in there and is highly flame retardant. Mold resistant as well. ?? Sound good anyone???
@@terrythomas790 I sealed all edges with polyurethane sealant. In my opinion, this was 90% of the improvement as I had many areas with air leakage. Then cut mineral wool insulation to fit. My basement is noticeably warmer after this project. My whole reason for doing this in the first place was to find out where mice were getting in (found it).
@@nwohiohomeinspector btw, thanks for the great video. I still learned from it! All of my frustrated feelings are gone now that i'm done with this project.
I've been in my house for almost thirty years. It's stucco on the outside, has a basement that gets heat from the furnace. It had kraft faced roll insulation at the rim joist when i bought so, it's probably been there quite a bit longer than that. i've never had this problem. Maybe because that's a crawl space. I can't tell if the floor is dirt.
@coreyfranco7060 R-30 is code for most crawlslpaces in north America. You'd be very hard pressed to attain this R level with foam board as it's essentially worthless.
@@coreyfranco7060, it's in Appendix O "Foam Plastic Diagrams". It is an state amendment to the IRC. Each state can make their own amendments to the IRC so it may not be required in your state. I'm in NC for reference.
Every XPS product I see available mentions for basement/indoor use, it CANNOT be left exposed. Needs to have fire break of 15min. How would you cover that on the rim joists?
Yep these vids are not oft to point out you should cut an equivalent size piece of drywall and glue it to the foam. Now the job has become a nice big pain in the ass.
Most building inspectors recommend UNFACE fiberglass insulation do to its fire rating. If you use foam board it must have an approved fire rating. If not it needs to be sealed up completely. Foam board will also trap moisture between itself and the rim joist. When you use any type of insulation your opening yourself up to trapping moisture between the insulation and rim joist due to outside moisture entering through the foundation wall. Always check with your local building inspector to see what he or she wants.
Foam board won't trap moisture if it's done properly. I think your whole fire rating theory is unjustified - your comparing two types of insulation at the rim joists, which I don't think is going to matter a whole lot if there's a fire ;)
Just speak to building inspectors about foam board being exposed, they will want to know its fire rating and how your going to give it a proper fire block.
@@thepinkdiamonds8370 , I understand what you're saying/getting at, but the building inspectors around here (and most I imagine, unless you're in a bigger city) don't care or even know about lol. I can't even fathom how many houses don't meet the fire ratings, you speak of, but I'm sure it's "quite a few" ;) I'm lucky to see a firewall in a garage lol. If it's of a concern, then use a fire rated foam board or similar. I know it certainly wouldn't be of concern to me for my house.
Northwest Ohio Home Inspections - ASPEC Residential Services, LLC , That’s what a state building code is all about. It doesn’t matter where you live in the state everybody should allows follow a unified code unless a inspector tells you otherwise.
@@thepinkdiamonds8370 Yes, that's what I said. I'm not saying you're wrong or right, but all inspectors/AHJ's that I know in my area do say otherwise and could care less about fire-rated insulation in a crawlspace.
Looks identical to my crawlspace. The guy who built my house extended the floor joists directly out over the rim joist and build a deck on top of those. We had flooding horribly earlier this year so we had to remove the decks to.install proper perimeter drainage. We almost removed the front deck with the Excavator, could you imagine how bad that would have been if so...would have ripped my whole house down.. now I'm trying to square off those floor joists along the front and install a proper ledger, huge gaps and wet insulation was stuffed in between the joists just like in this video. It's been a complete nightmare. I'm about 1/4 of the way done. Perimeter drainage is in, backfilled etc but now it's making everything right. Or as rigjt as I can anyways Some people just shouldn't build houses! Total pain in the a@@!
Weak methods are indeed a dime a dozen. Some are driven by ignorance, some by lazyness, and some by lack of available materials. It's an almost endless source to explore - a series that could be called Uncle Lowball Adventures [in bad construction].
I did this in my basement about 13 years ago when I moved in my house in 2009. I just went and checked and I’ve got ZERO moisture, mold, or discoloration happening. It’s not a problem for everyone so I’m leaving mine alone.
Everything with construction is very dependant on the area. You could possibly be fine where you are at, and the fact you went in your crawl space to check puts you better than 50% of people already. Chicago is an area that is constantly moist. Lake Michigan, and marshlands make the area fight moisture constantly. So we have to prepare for these things, where an area like Arizona deals very very little with moisture problems. Roofing is done different in the two areas and many codes dealing with freeze/thaw conditions will make codes different from area to area. This is a recommendation, and I do believe a very good one. Polystyrene (blue/purple) board does not hold moisture, where fiberglass insulation does. All these small, but important details, matter when deciding what to do to your home.
This is exactly what I did when I finished my own basement last year, replaced all the fiberglass batt with glued-in rigidboard and sprayfoam sealer. What a difference it made. Basement is warm and dry, heat bill is way less than what it was. Just wanted to reaffirm what this gent is saying.
Hi just a quick question. Are you saying it’s wise to remove all the fibreglass insulation in the basement and replace it with board insulation. My home basement came with Fiberglass and I’m thinking what’s the best to do. Should I keep the Fiberglass and frame it that way or should I remove it and replace with board before framing. Pls advise me. Thanks.
@lightning1086 if you have a Cement basement, the best option is to remove the fiberglass and add rigidboard to the concrete walls, tape the seams, spray foam around any gaps like joists, wiring, dryer vent, etc., then add your fiberglass back on, then vapor barrier.
I'm a professional installer and they don't sit right because they are too big and using a Kraft is better than an unfaced.. smaller squares fit beautifully and the paper on the bat helps tremendously..those "sandwiched" piece's belong as a blocker for a baffle on the roof..
Last time we remodeled, I had access to the crawl space and attic rim joists. Use airless to spray paint a good quality exterior paint (with mildewcide) the rim joist cubby hole area, including the end sections of the joists. Took about couple of hours and then went back and give it a second coat (dried pretty fast in the hot summer), sealing the seams and crevices. When the paint's all dried, came back to spray foam the seams and cracks. (spray foam cans) Then cover the entire rim joist area in attic with 6 mil clear plastic as moisture barrier, before sheetrock. The airless spray painting took about a half day; I used the other half day to spray paint the redwood fencing, so only had to clean the airless at the end of the day. For the rim joist paint, used OOPS paint where color doesn't matter; a $300 high quality exterior paint 5 gallons for around $30.
Hello, You should have told the buyers that the “blue board “ should be covered up with type x drywall. Blue board is highly combustible. Roxul works extremely well too. Agreed fiberglass is a poor insulation.
@@unityroad smiling, I understand. How about that little part about leaving 5" exposed to show if termites are climbing the foundation.... Just saying. Thanks for the pet name, its been a long time since I've been called that. Im ok, you ok?
So its ok to put insulation in a walls but not rim joist. Please make sense. Any wall that wet will mold/rot doesn't matter of insulation. Fix leak first!!! or source of dampness in basement.
Source of dampness in basement is warm and cold air meeting and condensing, not a leak. The rim joist area, unlike a wall, is virtually impossible to put a proper vapour barrier on. The sheet insulation is also the vapour barrier.
Won't condensation still build up at the median of temperature transfer. Won't there still ne that issue. And if it's sealed onto the joists than how will you inspect it once a year for the same problem. Does it solve that mold issue
I've just seen 2"x10" or 2"x12" cutoffs plugged into the space. I'd like to see the rim joists a 40 year old house that has been sealed wit foam before I would do that to my house.
I do not understand how companies build this way and it has not been fixed. We are in 2020's there is a better way to do it and has been for a long time. I took all mine down and spray foamed it in my basement. You could see daylight like he said you can feel the air. Should there be a code for sealing rim joist?
Yes, you're exactly right! However, this video isn't about ventilation, which is another detrimental condition ( as I've said in a 100 other comments here ;) )
Air penetration at the rim joist is negligible. I’ve yet to see anyone measure it or demonstrate it. The dirt that accumulates behind the insulation batting in from the inside (you can see filth flying around the air in your camera’s lighting). Heat transfer is the only concern. And any stiff insulation product-like rockwool batting-will do.
If the joists are embedded in the foundation, then I would not recommend this as it could trap moisture and rot the wood as well. Most people wouldn't have to worry about this but it's worth mentioning.
Every house i work in now has spray foam there. Its a pain when trying to drill for silcoxs or anything for that matter because you cant see any wires that may be in a bay.
You have two separate issues going on here: 1) insulation for the rim joist; and 2) the ability of the rim joist to dry. If you are going to use vapor-impermeable foam instead of fiberglass batt (permeable), the installation is going to have to be perfectly airtight and there's no such thing as a perfect wall. (If I was going to attempt it, it would be with several separately-applied layers of closed-cell spray foam.) If it's not perfectly airtight, you will still have vapor transfer condensing in the imperfections out near the rim and now with even less of a chance of drying out. The approach in my northern area is typically to ventilate the crawl space so there is no great temperature difference or dewpoint resulting at the rim. The crawlspace remains uninsulated and, instead, any pipes running through it are insulated and heated and the floor above is heavily insulated.
@@baxtronx5972 I would not be using any kind of sheet plastic inside or outside the house for this purpose for several reasons, including the same imperfections in installation that would be an issue using foam board.
I don’t have a crawl space, but I did remove pink “17 year old” stuff there and put rock wool and sealed with spray foam... will the rock wool cause issues ? Also I filled that whole space to the point of your blue board, so let’s say 3-5 pieces of rock wool,good/bad/doesn’t hurt?
The way they installed the band insulation to begin with looks terrible, I’m an insulator and we are picky on how it looks, it needs to be crisp and smooth and that looks like someone rushed and just guerrilla slammed it in there, if it’s not crisp and smooth it will not hold the R value, and the way it was folded like that means the air could just go straight under and around it, but yes generally blue board is best for bands.
Your seeing so much moisture because of a lack of insullation and not enough R value around the Band Board or Rim. Blue Board is Superior but it to isn't a guarantee against moisture. Particularly air gaps. Also moisture is a big problem with crawl spaces. I recommend check humidity. You will find inadequate drainage due to vapor barrier, lack of footing drain. Improper ventalation as well. Fiberglass will work it must fit well and be thick enough. I built many Freezer in a commercial environment. Foam is good but never for residential use. The Blue Board is Good if it is up off the floor of the crawl space several inches. I have seen more than one home with Stucco or a Blue Board insulation boards were used and termites enter between the masonry and the Blue Board. Cut it up off the ground or learn the hard way. I am not in favor of Fiberglass for freezers. I have demoed and remodeled large freezers. It takes a lotta fiberglass to Equel close cell foam Why not use close cell foam Blue Board and the like for Residential. When you see the Dead Bodies Removed from a home after a fire with their nostrils black as soot you will understand. Some idiots claim it won't burn. If it gets wicked and reaches kindling temps it is impossible to escape in the black soot. Industrial BC ret. G.C.
I too have been building for a while. Never seen mildew or mold cause by air transfer, if everything else is done within tolerances. The foam is great, but it’s highly flammable. Spray foam is even better. It makes a solid flex free glued together building. However, if you need or want to modify things, it’s a nightmare. Very easy to cut romex with any tool. So, R-19 in a 2x6 wall with type X 5/8 drywall, is my choice for applications.
I have been building Encapsulations from Knoxville Tn to Kingsport Tn for 15 years. Refreshing to hear a completely accurate report. You are truly better off with nothing, rather than fiberglass batts. The rim joists is where 20% of all heating and air conditioning loss comes from because , like he said, nothing is there but a 2 x 10. In almost 1/3 of all homes, you can see the sunlight in and around the band joists (same as rim joists) because the 2" board is too hard to cut (and there's a lot of cuts) , we use 1" Owens Corning board. We pop a 1-1/4" roofing nail in the middle of the board to hold it in place while we foam around it. It's time consuming, but if you pre-cut the boards at the shop, it goes faster. There are lots of non-standard spots and many places where pipes or wires go through. It's best to get accurate measurements for those, and cut them at the shop and write on the PM with a marker. Last two hints. 1) Leave a space above the foam board to shoot the foam into. Foam doesn't have anything to sit on if you don't, and if you're going to drive a roofing nail (a box at Lowes is $3.88) you can't get a hammer into that area. Poke the nail into the foam board first and use something as an extension to hit with a hammer. We have a one inch round lead pipe that's 10 inches long. Very last hint. Major cities Home Depot and Lowes will rent a Fogger and both sell Concrobium Mold Control ($37 gallon, or $9.50 for 16 oz spray bottle) It kills every mold spore instantly and no mold can grow on that lumber again.....EVER !!!! I can't say enough about this product. Whole families were seeing the allergy doctor until we fogged their crawlspace . Angie Hicks of Angie's list made a video BLASTING allergy doctors for NOT telling their clients to atleast have their crawl space looked at. They must have made her take it down. Lastly, an air quality specialist costs four hundred and fifty dollars, you spend seventy percent of your life inside your home breathing God knows what.... these dudes are good and they have the instruments..good luck with your home,
UnderStructureRepair damn man thanks for the knowledge
fetty guapo Quite Welcome. I've seen everything from a 34 year old couple with three kids have to abandon their home, doctors orders. And I've seen Radon at a level 12 kill a 40 year old woman (lawyer) and I THINK that bat guano killed another gentleman. Tin roofs are great, but if the contractor doesn't put this fiber-like material under the ridge cap, and bats decide to make it a satellite home? Well, this fella ended up with them in the walls and everything. Histoplasmosis kills people and that's what he had. Almost every tin roof contractor puts the stuff, but when they don't, man it's like Russia roulette. Should be inspected. Darn shame to see somebody house harm them, or worse. It troubles me.
What do you do about termite inspection? If you glue and seal blue board how will you ever be able to inspect for termites?
Troy Baker Good question : in Tenn. you can't take to board to the tops of the walls, as shown in this video. It must stop 4 inches below the tops of the walls. That's supposed to be so that termite inspectors can see mud tunnels. But I was a termite inspector too for nine years, and they prefer to come up through the dark, damp hollow block and eat from the inside out on the floor sill.
TN code says to use R10 , or 2 inches of foam board in the band joists. We don't do that for just the reason you described. We use only one once. That gives the termite inspector room to jam a screwdriver into the floor sill to see if it's being attacked.
By the way, Termites were totally defeated with the advent of Termidor SC in 2004. It's so dafe, homeowners can get it online. I do not understand anybody having Termites these days. Treat you own home every ten years.
UnderStructureRepair Thanks for the info in your reply. Do you know of a good reference for a homeowner applying Termidor SC? I'll continue looking at the product website but often professionals and DIYers have good tips on product use. Finally, thanks to NWOHI for the original video!
Thanks for the visuals. Seeing quite a few bad takes here in the comments. Simple summary: the fiberglass does not stop air movement. Moist air from inside the crawl space moves through the fiber glass bat and condenses on the cold rim joist. It's not likely to dry, and that's where the wet and black staining comes from.
The solution here is to remove the fiberglass, cut and cobble rigid foam and seal the perimeter of the rigid foam blocks with spray foam. Care should be taken to choose the right rigid foam thickness for the climate zone to ensure the inside face of the foam remains above the due point. There are simple tables to find the proper thickness for your climate zone.
This topic has been covered repeatedly on the green building advisor website and fine home building podcasts.
@Fred Wills yes, and this is an important point. Exposed foam is to be covered with some sort of flame retarder. The easiest solution here is to get the foam with foil face on one side that is fire rated. It's only marginally more expensive than the standard foam and it's still readily available at the big box stores (at least here in the north east). Plywood, or drywall are also acceptable in most regions and versions of the code, but who wants to do that?
@@waltwinters9253foil faced is not fire rated bubs. Everything else I agree with.
Thanks! I was specifically referring to DOW Thermax which is foil faced and Class A Fire rated and can be left exposed. @@teamdada2194
If you have a good source that says otherwise please share I’d love to read it.
www.dupont.com/content/dam/dupont/amer/us/en/performance-building-solutions/public/documents/en/thermax-sheathing-pis-43-D100094-enNA.pdf
My house was done 35 years ago with the fiber glass, I pulled them out and didn't see any problems. I live in Wisconsin, that might make a difference.
Same here, climate controlled basement rather than a damp crawl space.
@@woohunter1same, New York my basement is dehumidified, connected to main house hvac. and no issues with batts at all
The problem is not with the fiberglass bat, but with improper installation and the lack of vapor barrier. If you're using fiberglass bat it should be cut to fit the space snuggly and a vapor barrier installed and sealed with acoustic sealant. No more air transfer.
In cases like this. With a good fitting batt, a person can also buy a closed cell spray kit and cover the insulation batt. Both adding insulation and proper Vapor barrier. Costs more though
If you want to avoid spray foam/foam board, rockwool batts do allow air transfer through the entirety of the batt unlike fiberglass.
When I insulate a band joist I start by caulking to stop the air infiltration as much as possible. I caulk the seam where the sill plate sits on the foundation, where the band joist sits on the sill plate, where the floor sits on the band joist, also there the floor joists hit the band joist (the nail holes leak). When you pull the pink insulation out you can see stains in it from all the air leaks. I used mineral wool the last time I did this because if a termite inspection is needed, they can move it out of the way without damage.
Spray foam or Styrofoam (blue board) to insulate the rim joist cavities (RJC), not a chance! Maybe you can get away with that Ohio or in the North but that’s a huge mistake in the mid-Atlantic and southern states where a risk of termites exist. Stay away from the blue board, use something of a better quality such as Hunter brand for the walls (it has dual sided fiber reinforced vapor barrier). Take the Hunter board up to within 2” of the top of the block/brick/cast wall and leave the 2” gap for a termite reveal. Next use RockWool insulation for the RJC to limit heat transfer, this allows for easy removal for termite inspection and it doesn’t absorb moisture as fiberglass will.
You want to take it to to the next level then insulate the ground 24” horizontally in from the wall around the full exterior perimeter of the wall. Cover the entire ground with a class 1 vapor retarder (20mil) with 6” overlap at the seams and tapped with 4” vapor tape. Install an appropriate sized dehumidifier that will remove around 80-100 pints of moisture per day on a dedicated GFCI outlet. Upgrade your access door to seal tight with weatherstripping and insulated on the inside.
Biggest take away for anyone reading this is to limit the use of spray foam in a crawlspace. I’ve seen spray foamed 6x6 beams with 80% rot because of trapped moisture. I’ve seen rim joists and joist tails completely decimated by termites and you could only tell by probing the wood with a wood probe (could actually stick a pencil through the lumber). Save the spray foam for inside the structure.
Moisture in the RJC is not from “air transfer” as suggested, it’s a dew point issue. The exterior framing, if constructed properly, should have house warp with taped seams such as Tyvek for a vapor barrier over all exterior sheathing.
Hmm query what about snow areas seen most of cabins up big bear floors are insulated with insulation held in place with wire loops made and bent for that pourpose
Bugs hate that RockWool insulation
Foam board gets frost/condensation behind it too. Seen it myself on a partially exposed basement in Wisconsin. The wall is better to breath.
If I put foam on my walls my entire house would fill with mold in one season.
We have rim joist batts in our 35 year old home and do not have any problems with moisture, mold, or other. The outside of the rim joist and side walls is covered with 1 inch Tuff-R foam, then Tyvek sheeting, then 1/2 inch t-111 siding. Works for us.
It's probably best to do inside and out if you use 1/2 inch foam on exterior
But if you go any thicker on the outside then you're right inside is not necessary.
Makes sense. If the inside surface of the rim does not get too cold then it will not drop below the dew point, hence no condensation.
How wet/dry is your basement/crawlspace?
The issue with bat insulation in rim joist is above that insulation is living space and. It will keep a cold floor 10 inches or so from the wall. As it's technically part of the outside not inside heated space now.
Do you live in a cold climate? If not, then obviously you wouldn't have issues. This only applies to cold climates.
We have no exterior foam, but I have a New York home and also batts. No problems at all. I’m positive if I remove one now I’d see no issues behind it. I do run a dehumidifier 365 days/year keeping basement at 50-55
Use Rockwool type bats and cut them to fit very very snug. Do around R25 to R30. You need the joists to breathe a little or trapped moisture will mold the joists. If the exterior is not Tyvek'd or sealed you will always have moist air intrusion.
I live in a cold climate and agree your summation is correct. Here we also need a poly (Visqueen) barrier anywhere low density foam or batting is used. We do not need or want to leave a strip of sill plate exposed for termite check because no termites here. Guess u don’t hv them either. I like your commment about being able to remove foamed-in sheet foam versus urethane sprayed foam. Good point. Cutting and can foaming is very labor intensive. You show a good example of how a good job looks. In a cold climate it would take 4 layers of 2 inch rigid foam to make me happy, with each layer can foamed. So I would bring in the urethane foam truck for almost all bays. I know u pointed out the batting moisture problem likely caused from vapor. I think u also mentioned the need to air seal the rim joists. In a multi story house there is a big stack effect with any air path from the basement. The man who built our house urethaned some sill bays, but in some bays he meticulously cut rigid foam blocks. Very neat precise cutting. Must hv had a hot wire. He did not can foam the cuts. During a remodel of ours we found his work. His hand custom cutting with no can foam was a BIG mistake. Terribly drafty. Found dead flys and yellow jacket small nests in locations one would swear a bug couldn’t get to. Harmless enough but the drafty issue I am sure stole much of the R value of his work. Thx for your vid. Good commentary from you.
Taping around vent box to reduce leaks into the space behind the drywall is a great tip!
The contractor used fiberglass in my home's rim joists and I found mildew-ish growths in some, plus the Northeast corner in the master bedroom would form ice on the wall. I tore out all the fiberglass and paid to have proper foam in place. Cost for my 1800 square foot home was $750.
Exactly. Also 1 1/2” strip to fill space below joists up to sill plate especially if it’s a block foundation. And zip tape the seams. Also at that point you can put the fiberglass back in.
When we finished our basement, I used batts in the rim joist, then cut plastic to fit over the batts. Embedded the edge of the plastic in acoustical sealant then even added staples to hold it all in place. About 5 years later we noticed one of the basement rooms was abnormally cool. Started investigating and removed from suspended ceiling tiles in the basement and noticed that the acoustical sealant which was supposed to remain flexible had hardened and let loose in some areas leaving gaps between the plastic and floor joists. Pulled the plastic and batt insulation away to find a 1” thick layer of ice on the rim joist. 😕. Ended up taking the entire ceiling down near the rim joist and pulling plastic and insulating everywhere from the rim joists luckily only found a few more problem spots. Ended up cleaning up what mold had appeared, dried everything out then spray foamed the whole perimeter. Should have just spent the money on spray foam in the first place, way quicker install and complete air tight.
The approved way to airseal an open space is 2mil plastic sheeting (white flame resistant type if exposed) taped at all edges with 3” white tape. We use this in metal buildings all the time.
Unfortunately using this for rim joists is difficult so I prefer 1” foam on the OUTSIDE of the rim joist but this is impossible on most retrofits.
Closed cell foam?
@@MrChadder007 closed cell foam is a good insulator but it will crack over time losing all air sealing qualities.
It is not acceptable as an air barrier that has to be inspected. Most rim joist insulation is not inspected, but might as well do it right I figure…
Cold-climate-liver (love it). Stack effect is real (and powerful). Vapour barrier is difficult to install as a defence at the rim joist (ten tubes of acoustic sealant later). I'm still assessing whether well-installed spray-foam will work better. As the house flexes from warm-humid to cold-dry I'm fairly certain cracks have been opening that I cannot see. Part of the problem is we over-"air condition" in hot weather and over-heat in the cold. We've only had a few decades to see what happens. Also...properly installed exterior insulation if you are doing a new-build (but investigate HVAC air exchange). In most districts these things are code where I live. If I were able to build a new house, I'm interested in insulated concrete forms...but you need a competent contractor. I'd also be happy with a tiny cabin and a wood stove, windows that open in the summer. Where I live it takes a century of shameful neglect before those things decay. I am fond of modern cooking/laundry appliances however..so get your electrical together..
The problem is high RH in an area with leakage, not batt insulation. Batt gets a bad rap because it’s in the right place at the wrong time (when air leaks and temp differentials are greatest. Too much humidity inside will result in condensation anywhere there is air leakage. Windows are no different. The rim leaks air just as any other area of a wood framed home. If you’re going to put any type of insulation in a joist pocket you need to make sure you first seal it so the batts can do their duty via thermal barrier. Batts are not sealers or vapor barriers, and when installed in a spot where it’s surrounding environment has high humidity with leakage, wahla you have condensed.
Exactly. I live in WNY and just pulled my non-vapor barrier rim joist fiberglass that was installed in the 70s to inspect things as I remodeled my unheated basement. The joists are perfect, no signs of dampness, no rot, no mold. Humidity drops like a rock in winter where I live. If your basement is occupied, then you need to seal the rims with a vapor barrier, just like the concrete walls should be. If not, then leaving them unsealed is fine. I run a dehumidifier set to auto mode all year... it keeps the basement humidity to under 45% or less.
air flow is good, that is not your problem. your problem is that you do not have vapor barrier on the inside of your insulation like you do everywhere else in the house, the air moves right through as warm, moist, air and then condensates into actual moisture once it leaves the zone of the heated house inside of the insulation. you should cut a piece of poly for every joist spacing and acoustical seal it into place. I seriously cant believe you are an inspector. Styro is a good idea but I would still do batt insulation first so that the wood can breath instead of placing styro foam directly to the wood, that will lock moisture up against the wood with no way to escape.
I have an older house with a basement that has no sill plate. The wood sits directly on top of the blocks. Three sides are below grade and one is exposed to the elements.
How do I insulate for that?
You're braver than me. I wouldn't touch fiberglass barehanded if I could help it. Especially if I suspect there's any kind of mold.
Our house had the fiberglass batt insulation at rim joist in our basement when we moved it. The house is 40 years old. The wood at the rim rotted and we got mice and wasps making nests in that insulation, entering from the rotted outside overhang.
My house has all those problems... Sad case
you need vapor barrier. the wood is the coldest in winter since the outside of the house is way below 55F which is the temperature of the ground inside. the moisture will condense on the cold wood surface. use plastic to block the moisture, then the fiberglass should work well.
This is correct, at least this is how we insulate houses in Sweden and other cold climate countries.
Vapor barrier or facing on fiberglass ins. Will trap moisture against the rim board and will cause wood rot !! Either use fiberglass R19 unfazed or spray foam 3 in. Which is the best way .
I live in Quebec. It gets very cold. My house has had this type of insulation since 1970. No issues.
@hugolafhugolaf
The insulation you have is ancient and outmoded. The insulation in this video is modern and far superior.
If you have the funds, an upgrade would work wonders. The difference will be night and day.
@@cquilty1Of course it is. It works though. My house, depsite dating back to 1970, is as energy efficient as any new home that is not built to super-stringent eco-criterias. And yes, I've had it tested. I was very surprised.
@@hugolafhugolaf
A 1983 Geo Metro still works. But nowhere near as well as a brand new Honda Accord.
The efficiency of insulation today compared with 1970 is vastly superior. Regardless of any eco pluses or otherwise.
@@cquilty1 No doubt, but I have no need to invest some significant money to gain that last % of efficiency
@@hugolafhugolaf
Ha! As already mentioned the difference would be night day. The square wheel is more useful/efficient than the insulation you have right now. Also, in the ensuing half a century plus since your insulation was installed, not only has insulation improved enormously, codes have changed and the R value requirements are far far higher
But as long as you still enjoy driving that dented, oil burning, rusty old Geo Metro with springs coming up through the seats, that's the main thing:)
I have tried to explain this to people doing bad basement renovations. Run that foam board straight up in to each cavity to the plywood above, and spray foam around. Then you have even vapor transfer along the backside of the foam to the outside. Then your crawlspace or basement will stay fairly warm and dry compared to the outside air temp. In basements, you are essentially building a "bucket" with no leaks that your framing and finishes will sit inside, and you leave the outside area with the concrete and above grade wood to transfer moisture up and out. I recommend DMX 1 step for floor surface prep and then install tongue and groove wood sheathing over that. Then you will be giving yourself a little insurance when you have moisture events in your house.
If moisture developed, and eventually rot, with the fiberglass batt why wouln't it with what is being proposed?
If he caulked each rim joist area then add fiberglass insulation may not have condensation that causes it to stick or turn to meldew.
Interesting. Wouldn't the blue board trap the moisture on the inside of the rim joist even worse though?
Just came across this & really like it. What would be better for this application, open or closed cell spray foam & for regular stud bays?
Why is the floor not insulated anyway? Especially in an area of the country that has a tendency to get harsh winters.
I love your adding the comment about removing the glass batt rim insulation and installing the Extruded Polystyrene rigid insulation with the spray foam sealing. To put it mildly, “you have your shit together”. I’m a semi-retired professional roofing and waterproofing consultant with over 40 years of actual field experience.
Should mention whether this is an encapsulated crawlspace or a vented one, dirt floor or poured concrete. All factors to consider as moisture control is key in crawlspace. If encapsulated you will need some sort of method to control humidity (dehumidifier) and if it is a dirt floor then want to look at installing (minimum) 6mil VB and running it 6-10" up the wall (on the warm side of the rigid insulation then tuct tape all the seams - that way any moisture that builds behind the rigid foam will stay under the VB.
VAPOR BARRIER & TUCK TAPE
One quick question...is the ground covered with a vapor barrier of some sort? Moisture and Argon gas will build up if the ground is not covered with some sort of vapor barrier. There is a 10 mil. heavy poly that is used under slabs, which can be used for this application. This will help to alleviate any ground moisture problems.
Now if each rim joist gap is sealed with vapor barrier and tuck tape, or accoustic caulk / sealant, using fiberglass insulation is just fine. Any moisture within that crawl space will be stopped. But if you constantly have moisture coming up from the soil, the joists could eventually rot too.
Vapor sealing the entire crawl space is what needs to happen.
Its not just the air transfer its the temperature difference causing condensation. Partially conditioned crawlspace with dehumidifier and blueboard, no fiberglass hydroscopic mold grower, use rock wool it breathes and is not hydroscopic and wont grow mold. Radiant barrier helps also. My crawlspace is at 65 degrees and 30 percent humidity. In house its 68 and 37 respectively.
In the northern climate the old timers would always say to not insulate basement walls from inside. The push of frozen earth on the concrete or worse block walls causes cracks even bulging. Insulation should be buried outside down at least 2.5ft . You can see after a snow that the outside perimeter ground around the bldg will be thawed this shows the heat loss but what is more expensive heat loss or hiring a foundation repair firm. Food for thought
This is a classic vapor barrier scenario, not a fiberglass specific issue. Lower cost solution is to use faced fiberglass cut to size, with the facing stapled and tucked as with any fiberglass install. The facing on fiberglass is generally around 1 perm. EPS offers nothing, you'd have to use XPS specifically (blue board as mentioned, Foamular, etc)
The question is where the damp come from. Is it from the outside or from inside.
In general I think it is a problem when the inspector likes or dislikes solutions. They are either accordingly to code, or not.
Looks like a dirt floor in there so it would be important to direct the downspout water over 10 feet from the foundation, make all the difference in how dry your crawl space is.
So what if the carpenter who built the building in the first place put the vapor barrier on correctly on the outside? Or what if you spray from the edges and then used the batt insulation? I think it's wrong to blame the insulation for poor prep work. You've obviously never removed blue board and seen the mold and mildew that's behind it.
curious to what the impact is on this type of insulation on termite inspections? I encapsulated my crawlspace and have two inch foam boards against the cinder blocks. my termite inspector wants to see more wood to verify no termite infestation. just curious, I've seen other videos advocating spray foam adjacent to the joists.
In this instance nothing you have spoken to will eliminate the rim joist being a condensation point and thus in need of a way drying after condensation. I'm not sure I know how to deal with it. Joseph Lstiburek does, though.
Would have liked to see what he recommended actually shown.
He mentions blue board with spray foam
@@rkalla He means a visual presentaion would be more informative than verbal description, and I also agree.
@@MT-cl3wx gotcha - thx
Imagine a blue rectangle with some sprayfoam lol
There should be a vapor barrier on the outside if not it was built wrong which would prevent that happening. The problem is there is way to much moisture in the crawl space and the fiberglass is soaking it up. The crawl space is the problem not the fiberglass.
No, the moisture is condensing on the inside of the rim joist. The barrier needs to go inside that.
@@Cotronixco Yes, that is the true understanding. Use vapor barrier to block the relatively warmer moisture inside the space.
@@gahnyun2016 Paper faced fiberglass insulation? Paper toward the warm side?
I don't think they had vapor barriers in the 19th century when my home was built
I saw somewhere that if you place the fiberglass batt into a kitchen catcher plastic bag and slash an X in the outside side. This is a fast way to add a vaper barrier like the upstairs walls.
Surely ventilate the crawl space to outside and insulate under the floor, with no ventilation from the house interior to crawl space. That way you will avoid warm moist air coming into contact with the cold rim joist.
Don't know if I solved the problem or made it worse as I've since moved from the house, in Ohio but when i moved in there was batted insulation at the rim joists, I removed it and placed each batt into a heavy plastic bag ,sealed it and replaced them. No loose insulation to shed, no dampness in the insulation and cleanly removable for inspection. Never saw (over 15 yrs.) wetness, insects or mold. Perhaps just lucky, perhaps a solution?
The problem is isn’t the bat insulation. The problem is moisture is getting in from the outside probably due to the lack of a proper vapor barrier and/or improper caulking on siding and trim. Look outside for the problem.
I see what you’re saying. If that was the case then the homeowner would probably be better off having no insulation at all there. Because at the beginning of the video he does talk about airflow which would mitigate condensation due to temperature gradient from outside to inside.
Tim Coleman I own a old farm house, and the way I did it was too insulate the all the floor joists. This keeps the heat out of the crawl space . And keeps the floors warm. Then the crawl space is vented well. This protects the home from moisture and keeps the crawl space nice and dry. If there is any pipes in the crawl space they too are wrapped very well with insulation. A little more work and money , but worth it. I have seen in some homes like mine where people did the same thing but also used plastic on the ground to hold off moisture. I think this is only needed if there are high water tables or low air flow do to trees and such.
tgmforum tgmforum because the crawl space is the same temp as the outside temp. There’s no condensation anywhere. You can also run plumbing between the floor and the insulation if your joist allow it. I used wrapped insulation and stapled it to the end of joist leaving a air space between floor and insulation.
tgmforum tgmforum vapour barrier. Staple 6mm plastic sheet to the floor joist. Seal it up 100% with tape
Im a waterproofer, 33. Years. Dealing with this, listen and listen good, the only way to control. Humidity in. Your. Crawl is 3dehumidifier, only way, vents don’t help, foams help with air intrusion , but cant. Control. Two. Different air. Temps. An$ that is what causes. All. The. Fuss,...
What about using Rockwool insulation there?
Where are the vents under the house to circulate air within the crawl space?
My basement is not finished and never will be, did put rock wool around the rim joists. And it make's a big difference in my heating bill
I did both with mine. Foam board insulation first with an adhesive, then Great Stuff around the perimeter of the foam board, then fiberglass.
Same. I also wrapped the fiberglass in plastic
@@dwalto1977 absolutely wrong thing to do with fibreglass batts. Look into how fibreglass batts actually work. The plastic negates any benefit to the batts. Not trying to be a smart ass. Rigid foam board is perfect in conjunction with expansion foam.Just put the insulation batts vertically after the rigid (room side). Because there is no air infiltration through the rigid insulation you will have no problems. Of course a vapour barrier on the warm side- done.
Missed the mark. The major issue is a lack of a vapor barrier.
If this crawl space is not heated/conditioned air, then we should be seeing vents in addition to good insulation and vapor barrier. This space has insulation on the foundation, so maybe it is heated. In this case, the vapor barrier belongs on the outside of the rim joist.
Would you recommend xps and stuffing the rim joist with mineral wool
Insulation?
@@infiniti2015 That'll work
I presume you haven't yet gotten to the part where a fire barrier must be on top (inside) of the foam blue board and how you do that.
I live in Idaho and that is not how we do crawlers. Air vents every 6-8 feet and R38 in the bays 6 mil on the ground. You get no mold unless standing water but that is a different problem. The floors stay warmer in the home. Condensation happens when cold meets warm with no air flow. so please show me the code on that one. It is a different zone than I know.
Why didn’t you show the uninformed how to cut peices and close cell spray foam around the edges?
Joisting on top of foundations walls like that is a bad idea in general. Even if you put rigid in there and make it air tight. That rim board is still going to be cold on the outside and hot on the inside and create condensation. Same thing will happen with spray foam. It just makes it all less visible.
Not if it's done right ;)
Yes but sorry to say. "Right" isnt sealing the condensation into that wood. The moisture content in that 2x10 rim board should be pretty much 0 before you seal that rigid insulation in there. If it was me doing that I'd be using 6" of ISO minimum so that rim board doesnt get cold enough to sweat and create moisture and condensation again. Even with 2" rigid on that concrete wall it's still considered a "cold room". In Vancouver B.C it is anyway
@J Wil for the most part we bolt on a ledger to the concrete and hang joists off that. For the most part joists only bear on the foundation when they cantilever beyond foundation. Things are different everywhere though. It's a very wet and humid climate here
So where you pulled that insulation off and saw mold on that wood...how do you now correct that? Kill mold and put another piece of wood over then spray foam?
Use a mold solution...I like: www.rmrsolutions.com/collections/diy-mold-removing-products?keyword=rmr%20solutions&gclid=CjwKCAjw38SoBhB6EiwA8EQVLs5vSryMqrAxhzBNWFqXFxYuOYgkt3A3MOeXAt4i-MGz8twCrGfzThoCSvMQAvD_BwE
Then insulate with foamboard and shoot a bead of spray foam around the perimeter of the foamboard to cover the gaps.
Thank you for confirming what exactly what I was thinking of doing in the basement
I've read just about every comment listed for this video. I've determined that there is NO WAY of learning how to do this correctly by watching these videos. People in the comments have listed about 2 dozen different ways that they think it should be done. You would think mankind would've more fully evolved on this topic by now. It can't possibly be this controversial! Oh well, I'll do it my own way.
Thanks for watching. Everything, and I mean everything, is debatable, in this day and age with the internet :) You can find support and controversy for anything you choose to. My experience is from things I see day in and day out. Did you read the blog I wrote in the comments?
I agree. I sat here searching for the correct way to insulate the rim joists. Two hrs later , still sitting here searching. Its because there are too many know it alls! Just getting more frustrated. lol. Besides actual spray foam, there seems to be no correct way.
My thought was to put 1" polystyrene, sealed around all edges, against the rim joist, and then putting in Roxul. It would fit snugly in there and is highly flame retardant. Mold resistant as well. ?? Sound good anyone???
@@terrythomas790 I sealed all edges with polyurethane sealant. In my opinion, this was 90% of the improvement as I had many areas with air leakage. Then cut mineral wool insulation to fit. My basement is noticeably warmer after this project. My whole reason for doing this in the first place was to find out where mice were getting in (found it).
@@nwohiohomeinspector btw, thanks for the great video. I still learned from it! All of my frustrated feelings are gone now that i'm done with this project.
@@jasonbohacek1130 was the a hole in the rim of your house?
I've been in my house for almost thirty years. It's stucco on the outside, has a basement that gets heat from the furnace. It had kraft faced roll insulation at the rim joist when i bought so, it's probably been there quite a bit longer than that. i've never had this problem. Maybe because that's a crawl space. I can't tell if the floor is dirt.
Im sticking with fiberglass. The foam can be deadly in any fire situation filling the home with extremely toxic smoke.
Rockwool is better, cut to fit tight.
You literally read my mind with this video!!! Thank you. I’ll be adding foam board to the rims. 👊
Only thing missing was the vapor barrier. Facing the heated side of room? comment please
This section should be r21? How do you achieve that with the foam board? Or is it r30?
@coreyfranco7060
R-30 is code for most crawlslpaces in north America. You'd be very hard pressed to attain this R level with foam board as it's essentially worthless.
By code you are supposed to leave the rigid foam insulation board below the top of the concrete block 2" to allow for termite inspection.
Where is that in the code book?
@@coreyfranco7060, it's in Appendix O "Foam Plastic Diagrams". It is an state amendment to the IRC. Each state can make their own amendments to the IRC so it may not be required in your state. I'm in NC for reference.
@@jtltet ok, i didn't remember seeing this in irc...
@@jtltet which state?
@@coreyfranco7060 NC
Should you leave airspace between the foam board and the rim joist as an air gap?
No
Putting plastic on the ground helps as well
I have the pink fiber glass insulation just like this. Better to just remove it and have nothing until I can purchase the hard foam board?
Every XPS product I see available mentions for basement/indoor use, it CANNOT be left exposed. Needs to have fire break of 15min. How would you cover that on the rim joists?
Yep these vids are not oft to point out you should cut an equivalent size piece of drywall and glue it to the foam. Now the job has become a nice big pain in the ass.
What about Rockwool?
Most building inspectors recommend UNFACE fiberglass insulation do to its fire rating. If you use foam board it must have an approved fire rating. If not it needs to be sealed up completely.
Foam board will also trap moisture between itself and the rim joist. When you use any type of insulation your opening yourself up to trapping moisture between the insulation and rim joist due to outside moisture entering through the foundation wall. Always check with your local building inspector to see what he or she wants.
Foam board won't trap moisture if it's done properly. I think your whole fire rating theory is unjustified - your comparing two types of insulation at the rim joists, which I don't think is going to matter a whole lot if there's a fire ;)
Just speak to building inspectors about foam board being exposed, they will want to know its fire rating and how your going to give it a proper fire block.
@@thepinkdiamonds8370 , I understand what you're saying/getting at, but the building inspectors around here (and most I imagine, unless you're in a bigger city) don't care or even know about lol. I can't even fathom how many houses don't meet the fire ratings, you speak of, but I'm sure it's "quite a few" ;) I'm lucky to see a firewall in a garage lol.
If it's of a concern, then use a fire rated foam board or similar. I know it certainly wouldn't be of concern to me for my house.
Northwest Ohio Home Inspections - ASPEC Residential Services, LLC , That’s what a state building code is all about. It doesn’t matter where you live in the state everybody should allows follow a unified code unless a inspector tells you otherwise.
@@thepinkdiamonds8370 Yes, that's what I said. I'm not saying you're wrong or right, but all inspectors/AHJ's that I know in my area do say otherwise and could care less about fire-rated insulation in a crawlspace.
Looks identical to my crawlspace. The guy who built my house extended the floor joists directly out over the rim joist and build a deck on top of those. We had flooding horribly earlier this year so we had to remove the decks to.install proper perimeter drainage. We almost removed the front deck with the Excavator, could you imagine how bad that would have been if so...would have ripped my whole house down.. now I'm trying to square off those floor joists along the front and install a proper ledger, huge gaps and wet insulation was stuffed in between the joists just like in this video. It's been a complete nightmare. I'm about 1/4 of the way done. Perimeter drainage is in, backfilled etc but now it's making everything right. Or as rigjt as I can anyways
Some people just shouldn't build houses! Total pain in the a@@!
Weak methods are indeed a dime a dozen. Some are driven by ignorance, some by lazyness, and some by lack of available materials. It's an almost endless source to explore - a series that could be called Uncle Lowball Adventures [in bad construction].
I did this in my basement about 13 years ago when I moved in my house in 2009. I just went and checked and I’ve got ZERO moisture, mold, or discoloration happening. It’s not a problem for everyone so I’m leaving mine alone.
Where do you live? I’m in eastern Washington and it’s not super dry here but we still get moisture/humidity
Everything with construction is very dependant on the area. You could possibly be fine where you are at, and the fact you went in your crawl space to check puts you better than 50% of people already. Chicago is an area that is constantly moist. Lake Michigan, and marshlands make the area fight moisture constantly. So we have to prepare for these things, where an area like Arizona deals very very little with moisture problems. Roofing is done different in the two areas and many codes dealing with freeze/thaw conditions will make codes different from area to area.
This is a recommendation, and I do believe a very good one. Polystyrene (blue/purple) board does not hold moisture, where fiberglass insulation does. All these small, but important details, matter when deciding what to do to your home.
This is exactly what I did when I finished my own basement last year, replaced all the fiberglass batt with glued-in rigidboard and sprayfoam sealer. What a difference it made. Basement is warm and dry, heat bill is way less than what it was. Just wanted to reaffirm what this gent is saying.
Hi just a quick question. Are you saying it’s wise to remove all the fibreglass insulation in the basement and replace it with board insulation. My home basement came with Fiberglass and I’m thinking what’s the best to do. Should I keep the Fiberglass and frame it that way or should I remove it and replace with board before framing. Pls advise me. Thanks.
@lightning1086 if you have a Cement basement, the best option is to remove the fiberglass and add rigidboard to the concrete walls, tape the seams, spray foam around any gaps like joists, wiring, dryer vent, etc., then add your fiberglass back on, then vapor barrier.
I'm a professional installer and they don't sit right because they are too big and using a Kraft is better than an unfaced.. smaller squares fit beautifully and the paper on the bat helps tremendously..those "sandwiched" piece's belong as a blocker for a baffle on the roof..
Last time we remodeled, I had access to the crawl space and attic rim joists.
Use airless to spray paint a good quality exterior paint (with mildewcide) the rim joist cubby hole area, including the end sections of the joists. Took about couple of hours and then went back and give it a second coat (dried pretty fast in the hot summer), sealing the seams and crevices. When the paint's all dried, came back to spray foam the seams and cracks. (spray foam cans) Then cover the entire rim joist area in attic with 6 mil clear plastic as moisture barrier, before sheetrock.
The airless spray painting took about a half day; I used the other half day to spray paint the redwood fencing, so only had to clean the airless at the end of the day.
For the rim joist paint, used OOPS paint where color doesn't matter; a $300 high quality exterior paint 5 gallons for around $30.
Hello, You should have told the buyers that the “blue board “ should be covered up with type x drywall. Blue board is highly combustible. Roxul works extremely well too. Agreed fiberglass is a poor insulation.
the wood framing is highly combustible too, oh and the sub floor plywood is combustible too...
@@trimbaker1893 Ok Dickhead every known Building inspection dept make you cover up foam, because of deadly fumes when burned.
@@unityroad smiling, I understand. How about that little part about leaving 5" exposed to show if termites are climbing the foundation.... Just saying. Thanks for the pet name, its been a long time since I've been called that. Im ok, you ok?
As far as Air Transfer - I caulk around the ends of joist to where the rim is AND top of mudsill to rim - all around. The Rockwool.
So its ok to put insulation in a walls but not rim joist. Please make sense. Any wall that wet will mold/rot doesn't matter of insulation. Fix leak first!!! or source of dampness in basement.
Source of dampness in basement is warm and cold air meeting and condensing, not a leak. The rim joist area, unlike a wall, is virtually impossible to put a proper vapour barrier on. The sheet insulation is also the vapour barrier.
Won't condensation still build up at the median of temperature transfer. Won't there still ne that issue. And if it's sealed onto the joists than how will you inspect it once a year for the same problem. Does it solve that mold issue
I've just seen 2"x10" or 2"x12" cutoffs plugged into the space. I'd like to see the rim joists a 40 year old house that has been sealed wit foam before I would do that to my house.
Thanks! You have pointed out some good points to ponder( for each) region n weather types!
I do not understand how companies build this way and it has not been fixed. We are in 2020's there is a better way to do it and has been for a long time. I took all mine down and spray foamed it in my basement. You could see daylight like he said you can feel the air. Should there be a code for sealing rim joist?
Most unconditioned crawl spaces have vents cut in to allow that air transfer so what about all that moisture. So I agree with Wallace Grommet below
Yes, you're exactly right! However, this video isn't about ventilation, which is another detrimental condition ( as I've said in a 100 other comments here ;) )
Would this still be an issue in a crawlspace that has a vapor barrier and dehumidifier?
Yes.
Air penetration at the rim joist is negligible. I’ve yet to see anyone measure it or demonstrate it. The dirt that accumulates behind the insulation batting in from the inside (you can see filth flying around the air in your camera’s lighting). Heat transfer is the only concern. And any stiff insulation product-like rockwool batting-will do.
Use Rockwool instead and cut it to size so it actually fits the space and doesn't fold over.
That dampness is shocking! I'll remember this lesson.
Would Killz and then flex insulation work?
If the joists are embedded in the foundation, then I would not recommend this as it could trap moisture and rot the wood as well. Most people wouldn't have to worry about this but it's worth mentioning.
Every house i work in now has spray foam there. Its a pain when trying to drill for silcoxs or anything for that matter because you cant see any wires that may be in a bay.
Yep, spray foam is the devil
You have two separate issues going on here: 1) insulation for the rim joist; and 2) the ability of the rim joist to dry. If you are going to use vapor-impermeable foam instead of fiberglass batt (permeable), the installation is going to have to be perfectly airtight and there's no such thing as a perfect wall. (If I was going to attempt it, it would be with several separately-applied layers of closed-cell spray foam.) If it's not perfectly airtight, you will still have vapor transfer condensing in the imperfections out near the rim and now with even less of a chance of drying out. The approach in my northern area is typically to ventilate the crawl space so there is no great temperature difference or dewpoint resulting at the rim. The crawlspace remains uninsulated and, instead, any pipes running through it are insulated and heated and the floor above is heavily insulated.
I would assume you could plastic your way to victory similar to what you would do on an outside wall for the rest of the house.
You are correct, ventilation is key
@@baxtronx5972 I would not be using any kind of sheet plastic inside or outside the house for this purpose for several reasons, including the same imperfections in installation that would be an issue using foam board.
Do u have a video on fixing the problem
Fantastic this is exactly the way they did on my new house, bat insulation in my rim joists guess I need to redo it
I don’t have a crawl space, but I did remove pink “17 year old” stuff there and put rock wool and sealed with spray foam... will the rock wool cause issues ? Also I filled that whole space to the point of your blue board, so let’s say 3-5 pieces of rock wool,good/bad/doesn’t hurt?
The way they installed the band insulation to begin with looks terrible, I’m an insulator and we are picky on how it looks, it needs to be crisp and smooth and that looks like someone rushed and just guerrilla slammed it in there, if it’s not crisp and smooth it will not hold the R value, and the way it was folded like that means the air could just go straight under and around it, but yes generally blue board is best for bands.
That blue stuff is flammable!! Why not put some Roxul in there instead since Roxul repels moisture
Your seeing so much moisture because of a lack of insullation and not enough R value around the Band Board or Rim. Blue Board is Superior but it to isn't a guarantee against moisture. Particularly air gaps. Also moisture is a big problem with crawl spaces. I recommend check humidity. You will find inadequate drainage due to vapor barrier, lack of footing drain. Improper ventalation as well. Fiberglass will work it must fit well and be thick enough. I built many Freezer in a commercial environment. Foam is good but never for residential use. The Blue Board is Good if it is up off the floor of the crawl space several inches. I have seen more than one home with Stucco or a Blue Board insulation boards were used and termites enter between the masonry and the Blue Board. Cut it up off the ground or learn the hard way. I am not in favor of Fiberglass for freezers. I have demoed and remodeled large freezers. It takes a lotta fiberglass to Equel close cell foam
Why not use close cell foam Blue Board and the like for Residential.
When you see the Dead Bodies Removed from a home after a fire with their nostrils black as soot you will understand. Some idiots claim it won't burn. If it gets wicked and reaches kindling temps it is impossible to escape in the black soot.
Industrial BC ret. G.C.
whats up where the foundation meets the ground ? looked like the plastic is a foot from the blue board...is that finished?
Cut/place properly whoever placed those shouldn’t be touching homes
I too have been building for a while. Never seen mildew or mold cause by air transfer, if everything else is done within tolerances. The foam is great, but it’s highly flammable. Spray foam is even better. It makes a solid flex free glued together building. However, if you need or want to modify things, it’s a nightmare. Very easy to cut romex with any tool. So, R-19 in a 2x6 wall with type X 5/8 drywall, is my choice for applications.
Not romex