This is the video I've been looking for! I had a few quotes and they were outrageous just for the ceiling. Hubbie and I want to use 3/4 board and figured there had to be some way to cut costs while stopping it from "raining" into my shop and having to clean all of my tools (woodworker). This is exactly what we thought we should do and I'm happy to have that confirmation. Unfortunately, we have to rent a scissor lift, but if we can do it all in a single day on just the ceiling, then we can do that. Add a dehumidifier if needed, and we'll be thousands of dollars short of what the lowest bid was. Thank you !!!
Hubby did that to his 20 x 40 metal tool shop. He built it over winter of his last year of work three years ago. I bought a ton of hot hands and feet. LOL. Over 6500 screws!! Then as he could he bought panels and insulation goop. He finished a few months ago!! We are looking forward to lower electric bills. LOL. The best part is I always know where he is! LOL. Take care and stay well.
After looking thru several other videos, and wasting time reading how to instructions that didn't make any sense at all, I finally found your video. Thank you. Good job. Just what I needed to know.
If you have a metal roof it is a lot better to ventilate it above the insulation below the metal roof if you can. The problem is metal is very cold so if it is cold the moisture will accumulate in the insulation and everything will rot, this is known as a sweating roof. You might get away with what the poster did if your humidity is low and you use a really good vapour barrier, however it is still a risk. There is a YT guy called Steve Roofer in London UK who has done some brilliant videos on warm roofs, cold roofs and hybrid roofs, which is what this is. They are well worth a watch because the roof has usually totally failed by the time you get a watermark showing up, or a couple of drips.
Thank you so much ! - This condensation problem on my metal roof has been driving me crazy for years and dripping water all over my metal work lathes and other machinery - I'm now going to buy the stuff needed and do this ! - Thanks bro for the tip ! Best of luck to you man ! 👍👍👍
I'm concerned that any condensation that happens between the board and the roof (in the ribs, for example) would be trapped against the purlins because of the spray-foam dams. Is this a real concern, and how might I address it? This is on an outdoor shed with 1x purlins.
The question is where is the moisture going? Unless you are ventilating or using a dehumidifier there will be moisture. It could be that it is forming above the insulation on the underside of the roof, if it is getting past the insulation. But if moist warm air is touching a cold surface it will condense. There are two roof designs used to prevent this. 1) Warm roof, 2) Cold Roof.
Will this work on my house that has a tin roof?? It leaks when it rains and then drips on the inside from sweating. I am so tired of buckets sitting around and mopping my ceiling.
I was just going to put fiberglass up in between my rafters for insulation, and then seal up my entire roof with thin plywood and then paint it. Shiuldnt have any condensation going up through the painted plywood.
3yrs on now and all still doing good no damp, mold or rotting timbers? Also was it just a stright tin roof and nothing between the insulation and roof like a menbrane of some sort or an air gap? Cheers
I appreciate your post. I have built a 15x22 shed. I built two trusses, one on each side using 2x6's. Then I used 2x6's going in between so that I could have a cath. roof inside. I'm trying to make this barn a bit sound proof so that music won't be real load on the outside. However I've already put some plastic wrapped 3"fiberglass insulation which I plan to put 1/2" styrofoam boards painted light blue as a finished ceiling with wood strips stained the color of the joist/purlins to give it a cabin look. I have lots of the 1/2"x 2'x4' that are bare styrofoam. After seeing this I believe I will remove the fiberglass and cover as you did then put the fiberglass a finish styrofoam back on it. How does that sound? Thanks again.
Question, I want to build a work shop myself and using metal roof but it won't be heated. Will I need to insulate the roof side of the building if it's not being heated? and yes I want to use metal roofing as well
I had the same thought as you. LOL But you can't leave that gap open if you have a ribbed metal or it will sweat and run down the foam boards into your wall.
Most people have a corrugated roof as opposed the more costly standing seam....! That's why most people will use closed cell spray foam! Directly applied to "painted/primed sheet metal. Then...no condensation, plus water/vaper barrier.....every thing good except the price!!
Hi there. I tried using the link to your previous video on this subject but it said the video was "private" and couldn't be viewed. Any chance you can make it public & share again. Looking to use your technique but want to make sure we're doing it correctly. Thanks
Hello! I have a gazebo with a metal roof, and I want to put a wooden ceiling underneath. The problem is that in the morning condensation forms under the sheet metal. Will installing glass wool or styrofoam between the sheet metal roof and the wood ceiling fix the problem?
Hi very impressive video. I have box section roof shed, smaller area than yours. Did you fit the boards directly to the steel roof please. Wouldn't you dtill get condensation Where's there's air gaps ?
You can use great stuff as glue and it fills in void's i spray it on thick and roll it so i have a even coat!!! I scrap off the excess i also smear it on the seems in a thin layer then i tape it with aluminum duct tape om going to try gorilla tape on my barn
I live in North Florida, where it is quite humid. I lived farther south and it isn't as bad up here, but its still bad. I bought a 16x38 all metal canopy in 2014 (2-1/2 posts and roof bows - corrogated metal roof running lengthwise rather than top to eave. And, I have had condensation that happens nearly every day. BTW the "floor" is crushed asphalt tailings. My question: since Polyiso has gotten so expensive and spray foam is ridiculously expensive. I have thought about using your method, but wonder if 1/2 or 3/4 EPS would work. The R value is said to be 1 something.
So just checking....no gap between the roof itself and the insulation board? Very different to what I've researched as it seems the common recommendation to enhance the insulation properties is to leave a gap. I note your point about not letting any air touch the roof re the condensation
Using rigid foam board like used in this video could work providing no air space between the foam board and the underside of the metal roof. A much better (and more permanent) "fix" would be to have 1" - 2" of closed cell (or open cell) foam professionally sprayed directly onto the underside of the metal roof to reduce/prevent the underside surface of the metal roof from reaching the dew point. Condensation will continue to form on the top side (outdoors) of the metal roof, but that is not a problem that needs a solution. The real condensation problem (on the underside) arises from the top side of the metal roof facing the night sky. The night sky (especially on clear nights) causes the outside surface temperature of the metal roof to become much colder than the ambient air temperature because the temperature of deep space is hundreds of degrees below zero. The severity of the condensation increases with flat roofs vs. pitched roof surfaces. You are probably aware that the degree of condensation isn't as severe on cloudy or partly cloudy nights. Physics dictates that more moves to less to become equal. The top side of the cold metal roof causes the underside of the metal roof to become cold enough to reach the dew point because of heat transfer (conduction). The dew point is the temperature at which water in vapor form condenses into liquid water droplets. Depending on the outdoor relative humidity (rh), there is a very good likelihood that condensation is also forming on the top side of the metal roof (as mentioned earlier). An example of surfaces facing the night sky is morning dew on the grass, but not on the grass under the leaves of trees due to the fact that grass under the 'shade" of the trees does not "see" the night sky. Another common example is car surfaces that face the night sky (I.e., hoods, tops, etc.) incur more condensation than the vertical surfaces (door panels, door windows). In northern climates, river water under bridges is the last to freeze because the water under the bridge does not "see" the night sky. Eventually, the below freezing air temperatures do freeze the water under the bridges. Going back to metal roofs, when you think about it, it's really simple physics, but I never see this explanation from metal roof "experts." Another (expensive) way to solve the metal roof condensation issue is to build a vented over-roof to prevent the metal roof from being exposed the night sky. Vented over-roofs are often a reliable solution for condensation issues, but the explanation as to why they solve condensation issues is never revealed, thus the science (physics) isn't spread to those people who could make this information common knowledge. Vented over-roofs in northern climates are also a reliable solution for eliminating ice dams providing the venting doesn't become blocked.
Nice video. I do wish you had shown a close up on the panel you are using though, it looks reflective in the video and maybe they don't sell this out here in the West. I do want to see your sweaty glue though - heading over there...
Here's a link to me doing the same thing last year in my home office from my Homestead channel. I go into more details in this video and it should give you more info... I hope! Thanks! ruclips.net/video/LPlaSg657uY/видео.html
Need vapor barrior metal roof and insulation. US there is vapior barr two stoes,. Europe people user string 1.5 from metal roof. connect like web. Then install insulation horizontal and vertial. Last string connect again. Sheet will have cracking.
I have an all metal RV carport that measures 40x14 wide. It's not closed on all sides and it drips a lot of water on the underside when it hits dew point. Do you think a closed cell spray foam might work? I don't think I could use panels cause the metal is not perfectly flat.
My problem is I have a quanset hut style roof and no wood rafters at all, basically a half round ceiling and even though garage wasn’t heated, the snow on the roof created a ton of moisture inside. So your idea won’t work for me , considering a spray on foam throughout either inside/outside, or both but not sure that will eliminate the problem.
In my garage I find the metal roof has a drip stop inside and it touches the wood beams and wets them. This is time will rot the beams. I hope you're not going to have the same issue.
My whole workshop is metal, framing and all, and I've been trying to come up with the best way to insulate it. This seems like a good plan, by using the spray foam to make it air tight and as extra reinforcement for holding the sheets in place. I'm not sure of the best way to attach it to my ceiling since I won't be able to use the shims to hold it in place while the adhesive dries...
I would go this route if I had a metal shop, too. The first idea that comes to mind for the roof is to use some prop sticks to hold the panels in place until the adhesive cures. Depending on your height some scrap wood may work, or you could also get longer sections of PVC pipe that would also work if it's taller. Just my first thoughts though... Thanks!
If your metal has raised ribs you will need to fill those with foam then cut off when dry flush with the metal roofing. Then if it were me I would use formica adhesive and paint the metal and one side of the sheet foam ...... when both tacky stick it up there the foam wont be heavy enough to pull loose. Then you could spray foam around the foam boards if you want.
I know this is a old comment but Whenever I need something to hold for a bit while waiting for a adhesive to dry I use CA glue with the applicator. Drys in seconds and super strong
What would you recommend if it was 66 inches between your steal rafters? We are having trouble with the condensation and we're hoping somebody else on here can help us with this 🙏🙏🤗
I don't understand why you didn't use OSB sheeting to cover the rafters lay-down tar paper and then install the metal roof. It would have been a lot stronger, more weather-proof and easier and safer to install the metal roofing.
I think this what I need but since water condenses on the underside of the slanted metal roof, shouldn’t it have a path to drain to a soffet type outlet? Or do you just let it drip on the foam insulation? Does it evaporate inside the space and not cause problems? Just asking.
Tim's reply below is correct. If sealed up correctly, no moisture will reach the metal. I've not had any issues at all since doing this to my workshop and it's been over a year now. :)
The moisture is in the air, it condenses when it contacts cooler surfaces. You won't stop this, regardless of how you seal. What you will do is allow the air between roof and insulation to reach the same temperature as the roof sheet as its insulated from the air in the workshop below. Without a temperature difference, the moisture in the trapped air won't condense. Although its not really trapped, most metal sheets are formed for strength, so there will normally be a route through the eaves. It would be difficult to make an air tight seal. Nice job, a lot easier than what I did today. I used 200mm earthwool supported by battens as I am covering with t & g cladding. Horrible job solo. Solid bats would be much easier, but they are very expensive here in the UK.
@@ericmass11 best was is shoot foam on it or lay roll vinyl on top it or you can buy a spray type insulation to shoot from inside and it will stop it but these foam boards does not fix it all it does is hide and make mold grow and very harmful
I am so glad I found you! Yours makes better sense and cheaper than what I was told as well as easier. Yesterday my husband says as I was waking up "check this out, we got mushrooms growing in the ceiling." Of course, I said a few choice words, had a mental conniption (just as Bill Cosby said "where your face splits") Lol. Yes, we're in a mobile home. Guess we have no choice but to start with a new one.
Any suggestions on a metal roof in a house to prevent condensation/frost that eventually drips onto cotton blown insulation on the floor of the attic and is also compromising the rafters? Any advice would be appreciated! I’m on a disability so I have fixed income! I can’t afford to have to replace the whole roof but if you have any ideas I would greatly appreciate them.
If you have a metal roof such as this, I would only suggest this method or spray foam insulation. You have to put a thermal break between the metal and your conditioned space to stop condensation.
@@Samcraftcom Thank you for the response. My only concern is Do you think the foam will be able to penetrate behind the rafters or I should say between the rafters and the metal?
Thanks for informative and fun to watch stuff. This video gave me some ideas, and hope in getting insulation and condensation sorted for our exposed corrugated iron roof here in the hot, dry Karoo. I have been worried about condensation, so this will definitely solve that, given our winter air humidity is around 30%. Definitely will be watching more. 🙂
@@Serenityserenity2024 I was hoping that it would stay at around 30%, because it is dry as heck. However, this year, the humidity did go up to the 80's. When I wrote this, I was quite concerned about the condensation. It seems though that Sam's tricks and our DIY stuff here worked. You live in a beautiful country @krisr1452 - regards!
Im from ohio and have had water dripping from my metal roof since I bought the house never could come up with a way to stop it till I seen your video I am hoping to try this soon so I can put drywall back up in the room and use it as my family room thanks for the information and as always keep up the good work!!!! 🙂🤘
I suspect your real problem is a lack of proper ventilation, in your attic area and/or a lack of insulation, above your ceiling. I had the same problem with my house (built in 1953). When I moved in it had sagging ceilings, due to what i mentioned. I installed two 14" turbines (house is 30' x 30'). Now, the humidity, which escapes into the attic is ventilated out. Dry attic.
@@MrBmill25: Yes, that's the whole idea. Moisture from inside your house accumulates in the attic. If it has nowhere to go, it will condensate on the wood, the insulation and the plaster or drywall, of your ceiling, causing great damage (and mold). Install a couple turbines and the moisture will get sucked out. Put them as high as you can and make sure they stick up above the roof line and are standing vertical. Don't forget to add more insulation, above your ceiling. You can never have too much insulation. PS: NEVER EVER cover the turbines. They must remain open year round, to do their job.
Hi Sam, just caught your channel for first time, am impressed and have subscribed with a few likes already, my tools get rust easily as it’s high humidity in Scotland and in heated wood shop, just retired last year hence wood shop/ man cave, have you any tips or method of preventing rust on tools. Thanks
I really don’t think that is a fire safe barrier on that foam board. I’ve been in construction a long time, foam ALWAYS has to be behind sheetrock because of its high fire danger. When foam burns it puts off toxic gasses, in the case of this foam cyanide. Point 2: hard foam is not a vapor barrier, it will crack over time and allow warm moist air to intrude.
Dude I built a huge vet clinic big metal building then put a drop ceiling in it , I hired the metal building out and my crew did the rest , winter came and when they turned the heater on it looked like it was raining everywhere . The building co didn't put a vapor barrier under the tin. Long story short I had to hire a spay foam co to spray the under side of roof metal and replace a lot of tile.
Karey Bear pretty sure it was. Thing is the city wouldn't let me build the post farm I had plans on that would have had 3/4 inch foil back because I didn't have a architecture stamp and the metal building company said I didn't need any.
That won’t stop condensation it’s just going to reroute and trap water. You’ll see corrosion, just a matter of time. Temperature in garage is Still lower than outside temperature. You’ve got gaps between foam and metal
The foil will give you a lot better reflectivity with an air gap ultimately I have mine in my house underneath the trusses so I have 3 and 1/2 in I've lowered the temperature in a single story home almost 55°, the hottest temperature my house attic got last year could have a wireless smaller was 112° in Georgia pretty impressive I love me some The shield but she got to have the air gap if it's the hered directly to the phone board it doesn't work but only a tenth of %. You don't believe me it's actually printed on the phone board on some of them and those readings come from Ashare the people that do all air conditioning regulations. All and all good video
@@Samcraftcom It still has to have sweating thats what metal does when temps fall or rains all this does is direct it to another spot example wood that in time will decay , This is good ideal to rerun water to a drip point but it does not stop sweating , all tin will do it even a carport
NOT GOOD AT ALL. That’s actually the Rich Mans way to do it. The wooden trusses are probably all absorbing the moisture now. They WILL ROT over time. Eventually the steel roof will start loosening up, leaking more and one day blow right off. At that point it will cost you a fortune. You need a vapor barrier between the lumber and the steel.
Well, now you have closed the spaces, to the outside, at the top and bottom of the roof panels, where is your accumulated humidity going to go? Accumulated humidity is not good for your materials, tools or green wood you are trying to dry. I know i am stating the obvious but I do that because I often miss the obvious. I know you did this at your old house but you didn't stay there long enough, to see the long term results. You really should have installed a ceiling, with insulation and vapor barrier. That way you would have a properly ventilated attic space and no condensation. The original build, of the building was as a shed, not a workspace. When you are working in there, you sweat and all your wood is giving off moisture, as well, even in the winter. It has to go somewhere, but now it can't.
All you did was to conceal the condensation between the metal and the foam. I think you also said to use any construction adhesive for the foam. Can't do that. Any adhesive must be approved for the type of foam board used. Others will eat the foam.
This is the video I've been looking for! I had a few quotes and they were outrageous just for the ceiling. Hubbie and I want to use 3/4 board and figured there had to be some way to cut costs while stopping it from "raining" into my shop and having to clean all of my tools (woodworker). This is exactly what we thought we should do and I'm happy to have that confirmation. Unfortunately, we have to rent a scissor lift, but if we can do it all in a single day on just the ceiling, then we can do that. Add a dehumidifier if needed, and we'll be thousands of dollars short of what the lowest bid was. Thank you !!!
Hey, I'm happy to help!! This was done several years ago, but never gave me any issues or problems! Best of luck!
Hubby did that to his 20 x 40 metal tool shop. He built it over winter of his last year of work three years ago. I bought a ton of hot hands and feet. LOL. Over 6500 screws!! Then as he could he bought panels and insulation goop. He finished a few months ago!! We are looking forward to lower electric bills. LOL. The best part is I always know where he is! LOL. Take care and stay well.
After looking thru several other videos, and wasting time reading how to instructions that didn't make any sense at all, I finally found your video. Thank you. Good job. Just what I needed to know.
What about suggestion when used over a patio?
I personally would have put a plywood base on rafters and used a vapor barrier. Your method is extremely labor intensive.
This is probably a solution for a problem that became apparent after the build was complete.
Do you not need to have a gap between the board? This is what I’ve been advised
It's a little late after the fact, but yes ..that's how it should be done in the first place.
If you have a metal roof it is a lot better to ventilate it above the insulation below the metal roof if you can. The problem is metal is very cold so if it is cold the moisture will accumulate in the insulation and everything will rot, this is known as a sweating roof. You might get away with what the poster did if your humidity is low and you use a really good vapour barrier, however it is still a risk. There is a YT guy called Steve Roofer in London UK who has done some brilliant videos on warm roofs, cold roofs and hybrid roofs, which is what this is. They are well worth a watch because the roof has usually totally failed by the time you get a watermark showing up, or a couple of drips.
Thank you so much ! - This condensation problem on my metal roof has been driving me crazy for years and dripping water all over my metal work lathes and other machinery - I'm now going to buy the stuff needed and do this ! - Thanks bro for the tip ! Best of luck to you man ! 👍👍👍
I'm concerned that any condensation that happens between the board and the roof (in the ribs, for example) would be trapped against the purlins because of the spray-foam dams. Is this a real concern, and how might I address it? This is on an outdoor shed with 1x purlins.
The question is where is the moisture going? Unless you are ventilating or using a dehumidifier there will be moisture. It could be that it is forming above the insulation on the underside of the roof, if it is getting past the insulation. But if moist warm air is touching a cold surface it will condense. There are two roof designs used to prevent this. 1) Warm roof, 2) Cold Roof.
Will this work on my house that has a tin roof?? It leaks when it rains and then drips on the inside from sweating. I am so tired of buckets sitting around and mopping my ceiling.
I was just going to put fiberglass up in between my rafters for insulation, and then seal up my entire roof with thin plywood and then paint it. Shiuldnt have any condensation going up through the painted plywood.
3yrs on now and all still doing good no damp, mold or rotting timbers?
Also was it just a stright tin roof and nothing between the insulation and roof like a menbrane of some sort or an air gap?
Cheers
The foil face on the insulation reflects the light back into the shop too. Bonus feature.
Yep!
It's nice to know that this has worked well. My shop drop ceiling has been ok. But adding the solar fan really made the difference.
I'd like to add something similar to my shop for summer. It's going to get hot in there with the lack of airflow now. 😬
@@Samcraftcom accept one of the solar light reviews and take the solar panel haha.
I appreciate your post. I have built a 15x22 shed. I built two trusses, one on each side using 2x6's. Then I used 2x6's going in between so that I could have a cath. roof inside. I'm trying to make this barn a bit sound proof so that music won't be real load on the outside. However I've already put some plastic wrapped 3"fiberglass insulation which I plan to put 1/2" styrofoam boards painted light blue as a finished ceiling with wood strips stained the color of the joist/purlins to give it a cabin look. I have lots of the 1/2"x 2'x4' that are bare styrofoam. After seeing this I believe I will remove the fiberglass and cover as you did then put the fiberglass a finish styrofoam back on it. How does that sound? Thanks again.
Question, I want to build a work shop myself and using metal roof but it won't be heated. Will I need to insulate the roof side of the building if it's not being heated?
and yes I want to use metal roofing as well
I found contact cement worked well. You can get it by the gallon and slap it on both surfaces. It aint coming off once you stick it on.
Awesome! I did have issues with the construction glue sticking. Thanks!
I had the same thought as you. LOL But you can't leave that gap open if you have a ribbed metal or it will sweat and run down the foam boards into your wall.
@@Val-ee4hd that's exactly what I was wondering...!
Unless his roof was flat sheet metal
Most people have a corrugated roof as opposed the more costly standing seam....! That's why most people will use closed cell spray foam! Directly applied to "painted/primed sheet metal. Then...no condensation, plus water/vaper barrier.....every thing good except the price!!
Should read"air/vapor barrier"
Hi there. I tried using the link to your previous video on this subject but it said the video was "private" and couldn't be viewed. Any chance you can make it public & share again. Looking to use your technique but want to make sure we're doing it correctly. Thanks
Hello! I have a gazebo with a metal roof, and I want to put a wooden ceiling underneath. The problem is that in the morning condensation forms under the sheet metal. Will installing glass wool or styrofoam between the sheet metal roof and the wood ceiling fix the problem?
Hi very impressive video. I have box section roof shed, smaller area than yours. Did you fit the boards directly to the steel roof please. Wouldn't you dtill get condensation Where's there's air gaps ?
You can use great stuff as glue and it fills in void's i spray it on thick and roll it so i have a even coat!!!
I scrap off the excess i also smear it on the seems in a thin layer then i tape it with aluminum duct tape om going to try gorilla tape on my barn
Thank you for the video. I have the same problem. Any link to your previous (one year earlier) video? Thanks
Thanks, drips on machinery and electrical stuff is just freak out time.
What would these boards be called in the UK
You should use a glue thats made for foam. Construction adhesive or DSA20 will eventually eat the foam over time.
I live in North Florida, where it is quite humid. I lived farther south and it isn't as bad up here, but its still bad. I bought a 16x38 all metal canopy in 2014 (2-1/2 posts and roof bows - corrogated metal roof running lengthwise rather than top to eave. And, I have had condensation that happens nearly every day. BTW the "floor" is crushed asphalt tailings. My question: since Polyiso has gotten so expensive and spray foam is ridiculously expensive. I have thought about using your method, but wonder if 1/2 or 3/4 EPS would work. The R value is said to be 1 something.
Curious if it's better to simply install the iso board before putting on the metal roofing?
My tin roof inside is always wet. Should I dry it first? Then, put the insulation up? And to confirm, you're saying it will never be wet again?
What state do u live in? Asking for relative humidity... Thanks!
So just checking....no gap between the roof itself and the insulation board? Very different to what I've researched as it seems the common recommendation to enhance the insulation properties is to leave a gap. I note your point about not letting any air touch the roof re the condensation
Correct -- no gap for what I did... which is very non-conventional, but has worked well.
@@Samcraftcom awesome, thank you!
Any advice on how to keep it from dripping in the winter when there is snow and ice atop ? Thanks in advance for any reply.
Yes - your roof needs to be ventilated above the insulation and below the metal roof.
Using rigid foam board like used in this video could work providing no air space between the foam board and the underside of the metal roof. A much better (and more permanent) "fix" would be to have 1" - 2" of closed cell (or open cell) foam professionally sprayed directly onto the underside of the metal roof to reduce/prevent the underside surface of the metal roof from reaching the dew point. Condensation will continue to form on the top side (outdoors) of the metal roof, but that is not a problem that needs a solution.
The real condensation problem (on the underside) arises from the top side of the metal roof facing the night sky. The night sky (especially on clear nights) causes the outside surface temperature of the metal roof to become much colder than the ambient air temperature because the temperature of deep space is hundreds of degrees below zero. The severity of the condensation increases with flat roofs vs. pitched roof surfaces. You are probably aware that the degree of condensation isn't as severe on cloudy or partly cloudy nights. Physics dictates that more moves to less to become equal. The top side of the cold metal roof causes the underside of the metal roof to become cold enough to reach the dew point because of heat transfer (conduction). The dew point is the temperature at which water in vapor form condenses into liquid water droplets. Depending on the outdoor relative humidity (rh), there is a very good likelihood that condensation is also forming on the top side of the metal roof (as mentioned earlier). An example of surfaces facing the night sky is morning dew on the grass, but not on the grass under the leaves of trees due to the fact that grass under the 'shade" of the trees does not "see" the night sky. Another common example is car surfaces that face the night sky (I.e., hoods, tops, etc.) incur more condensation than the vertical surfaces (door panels, door windows). In northern climates, river water under bridges is the last to freeze because the water under the bridge does not "see" the night sky. Eventually, the below freezing air temperatures do freeze the water under the bridges. Going back to metal roofs, when you think about it, it's really simple physics, but I never see this explanation from metal roof "experts."
Another (expensive) way to solve the metal roof condensation issue is to build a vented over-roof to prevent the metal roof from being exposed the night sky. Vented over-roofs are often a reliable solution for condensation issues, but the explanation as to why they solve condensation issues is never revealed, thus the science (physics) isn't spread to those people who could make this information common knowledge. Vented over-roofs in northern climates are also a reliable solution for eliminating ice dams providing the venting doesn't become blocked.
I used Foil Bubble wrap and 1" Foam Board
I have a box truck build and have been racking my head trying to figure out how to prevent that sweat !
This should work well for it!
Baby if your in Alabama I'll fix it for u for dinner one afternoon
@@waynewilliams5802 creepy
Does this foam get soaked over the months/years?
What would be the goam type (im in Europe)?
Thanks
I was in this workshop for three years and never had issues with it.
Nice video. I do wish you had shown a close up on the panel you are using though, it looks reflective in the video and maybe they don't sell this out here in the West. I do want to see your sweaty glue though - heading over there...
Here's a link to me doing the same thing last year in my home office from my Homestead channel. I go into more details in this video and it should give you more info... I hope! Thanks! ruclips.net/video/LPlaSg657uY/видео.html
Need vapor barrior metal roof and insulation. US there is vapior barr two stoes,. Europe people user string 1.5 from metal roof. connect like web. Then install insulation horizontal and vertial. Last string connect again. Sheet will have cracking.
I have an all metal RV carport that measures 40x14 wide. It's not closed on all sides and it drips a lot of water on the underside when it hits dew point. Do you think a closed cell spray foam might work? I don't think I could use panels cause the metal is not perfectly flat.
I think that would be perfectly fine, yeah!
My problem is I have a quanset hut style roof and no wood rafters at all, basically a half round ceiling and even though garage wasn’t heated, the snow on the roof created a ton of moisture inside. So your idea won’t work for me , considering a spray on foam throughout either inside/outside, or both but not sure that will eliminate the problem.
In my garage I find the metal roof has a drip stop inside and it touches the wood beams and wets them. This is time will rot the beams. I hope you're not going to have the same issue.
Why not use attic baffles, and just then put up bats of insulation?
Does this stop the condensation completely or just make an umbrella for your tools?
I've had no issues or signs of issues in the years since doing this. I consider it a success.
🤔 How does a little insulation change the condensation problem?
By preventing slightly warm air from making contact with a cold surface. Isn't that what creates condensation?
My whole workshop is metal, framing and all, and I've been trying to come up with the best way to insulate it. This seems like a good plan, by using the spray foam to make it air tight and as extra reinforcement for holding the sheets in place. I'm not sure of the best way to attach it to my ceiling since I won't be able to use the shims to hold it in place while the adhesive dries...
I would go this route if I had a metal shop, too. The first idea that comes to mind for the roof is to use some prop sticks to hold the panels in place until the adhesive cures. Depending on your height some scrap wood may work, or you could also get longer sections of PVC pipe that would also work if it's taller. Just my first thoughts though... Thanks!
If your metal has raised ribs you will need to fill those with foam then cut off when dry flush with the metal roofing. Then if it were me I would use formica adhesive and paint the metal and one side of the sheet foam ...... when both tacky stick it up there the foam wont be heavy enough to pull loose. Then you could spray foam around the foam boards if you want.
@@Val-ee4hd will that adhesive take the heat?
I know this is a old comment but Whenever I need something to hold for a bit while waiting for a adhesive to dry I use CA glue with the applicator. Drys in seconds and super strong
What would you recommend if it was 66 inches between your steal rafters? We are having trouble with the condensation and we're hoping somebody else on here can help us with this 🙏🙏🤗
Whatever works!! Good job. Not sure about the spray foam. Makes a mess. So nothing between roof and wood. Ok. Thanks. Frank
Thank you so very much, I needed this information. God bless you ☺️
Glad it was helpful!
I don't understand why you didn't use OSB sheeting to cover the rafters lay-down tar paper and then install the metal roof. It would have been a lot stronger, more weather-proof and easier and safer to install the metal roofing.
I wish I had, but for whatever reason didn't back when I built the shop. Probably a lack of funds at the time -- can't remember. :)
I think this what I need but since water condenses on the underside of the slanted metal roof, shouldn’t it have a path to drain to a soffet type outlet? Or do you just let it drip on the foam insulation? Does it evaporate inside the space and not cause problems? Just asking.
If the warmer temps & moisture doesn't get to the metal it won't sweat. That's why it needs to be sealed well
Tim's reply below is correct. If sealed up correctly, no moisture will reach the metal. I've not had any issues at all since doing this to my workshop and it's been over a year now. :)
The moisture is in the air, it condenses when it contacts cooler surfaces. You won't stop this, regardless of how you seal. What you will do is allow the air between roof and insulation to reach the same temperature as the roof sheet as its insulated from the air in the workshop below. Without a temperature difference, the moisture in the trapped air won't condense. Although its not really trapped, most metal sheets are formed for strength, so there will normally be a route through the eaves. It would be difficult to make an air tight seal. Nice job, a lot easier than what I did today. I used 200mm earthwool supported by battens as I am covering with t & g cladding. Horrible job solo. Solid bats would be much easier, but they are very expensive here in the UK.
@@keith7976 thanks!
Are you sure, you’re not just trapping the condensation?
They are it will lead to mold and can be very harmful in future
@@kevinramey4226 whats the proper fix
@@ericmass11 best was is shoot foam on it or lay roll vinyl on top it or you can buy a spray type insulation to shoot from inside and it will stop it but these foam boards does not fix it all it does is hide and make mold grow and very harmful
every thing need air space or air pocket to breath
Breather type building paper
I am so glad I found you! Yours makes better sense and cheaper than what I was told as well as easier. Yesterday my husband says as I was waking up "check this out, we got mushrooms growing in the ceiling." Of course, I said a few choice words, had a mental conniption (just as Bill Cosby said "where your face splits") Lol. Yes, we're in a mobile home. Guess we have no choice but to start with a new one.
wait till you have mold under the tin and it kills you over time
If the roof was boarded out first, say with OSB, then metal sheeting put on top would that prevent condensation.? I wish this video was longer tho 😁
It would, but you would also want to have an underpayment between the osb and metal roofing-something like tar paper or similar.
@@Samcraftcom. I assume you mean underlayment lol 😝
fur strips help with thermal break.
Good idea
Love your shows. Question: Why not put more insulation in ceiling of work shop like in soap shack?
I mentioned the workshop and insulation in the latest shop shack video. :) There will be insulation... very soon. :)
Any suggestions on a metal roof in a house to prevent condensation/frost that eventually drips onto cotton blown insulation on the floor of the attic and is also compromising the rafters? Any advice would be appreciated! I’m on a disability so I have fixed income! I can’t afford to have to replace the whole roof but if you have any ideas I would greatly appreciate them.
If you have a metal roof such as this, I would only suggest this method or spray foam insulation. You have to put a thermal break between the metal and your conditioned space to stop condensation.
@@Samcraftcom Thank you for the response. My only concern is Do you think the foam will be able to penetrate behind the rafters or I should say between the rafters and the metal?
No vapor barrier huh? That's what I was looking for.
I'm in sweet home Alabama. Will this trick work on the Alabama/ Tennessee border?
Don't see why not! We're in NC here. :)
Thanks for informative and fun to watch stuff. This video gave me some ideas, and hope in getting insulation and condensation sorted for our exposed corrugated iron roof here in the hot, dry Karoo. I have been worried about condensation, so this will definitely solve that, given our winter air humidity is around 30%. Definitely will be watching more. 🙂
is 30% a lot in Karoo? here in Ireland it gets to 90% all year round 😲
@@Serenityserenity2024 I was hoping that it would stay at around 30%, because it is dry as heck. However, this year, the humidity did go up to the 80's. When I wrote this, I was quite concerned about the condensation. It seems though that Sam's tricks and our DIY stuff here worked. You live in a beautiful country @krisr1452 - regards!
Ventilation is key👍
That's awesome thanks
Im from ohio and have had water dripping from my metal roof since I bought the house never could come up with a way to stop it till I seen your video I am hoping to try this soon so I can put drywall back up in the room and use it as my family room thanks for the information and as always keep up the good work!!!! 🙂🤘
Awesome (not for the leak, but for this video helping you)!! I hope it works out well! Thanks!
I suspect your real problem is a lack of proper ventilation, in your attic area and/or a lack of insulation, above your ceiling.
I had the same problem with my house (built in 1953). When I moved in it had sagging ceilings, due to what i mentioned.
I installed two 14" turbines (house is 30' x 30'). Now, the humidity, which escapes into the attic is ventilated out.
Dry attic.
@@zapa1pnt does this help with condensation in the winter? That's my problem right now.
@@MrBmill25: Yes, that's the whole idea.
Moisture from inside your house accumulates in the attic. If it has nowhere to go, it will condensate on the wood, the insulation and the plaster or drywall, of your ceiling, causing great damage (and mold). Install a couple turbines and the moisture will get sucked out. Put them as high as you can and make sure they stick up above the roof line and are standing vertical.
Don't forget to add more insulation, above your ceiling. You can never have too much insulation.
PS: NEVER EVER cover the turbines. They must remain open year round, to do their job.
Great job Sam.
Thanks Kevin!
Hi Sam, just caught your channel for first time, am impressed and have subscribed with a few likes already, my tools get rust easily as it’s high humidity in Scotland and in heated wood shop, just retired last year hence wood shop/ man cave, have you any tips or method of preventing rust on tools. Thanks
I wish I could give you some great tips, but I struggle with the same problems in my shop. :(
Would have liked to see pictures
I really don’t think that is a fire safe barrier on that foam board. I’ve been in construction a long time, foam ALWAYS has to be behind sheetrock because of its high fire danger. When foam burns it puts off toxic gasses, in the case of this foam cyanide.
Point 2: hard foam is not a vapor barrier, it will crack over time and allow warm moist air to intrude.
Thanks for the sub mate. Love your stuff.
Thanks! Glad to have you here, too!
Samcraft perfect video for what I need. I’ll be insulating my workshop at the end of this month.
Dude I built a huge vet clinic big metal building then put a drop ceiling in it , I hired the metal building out and my crew did the rest , winter came and when they turned the heater on it looked like it was raining everywhere . The building co didn't put a vapor barrier under the tin. Long story short I had to hire a spay foam co to spray the under side of roof metal and replace a lot of tile.
Oh that would be terrible!!! True spray foam would be the best by far. Thanks for the comment!!
Karey Bear pretty sure it was. Thing is the city wouldn't let me build the post farm I had plans on that would have had 3/4 inch foil back because I didn't have a architecture stamp and the metal building company said I didn't need any.
Thanks
Also, condense is a verb. Condensate is a noun.
You are a very smart and talented young man.
Thank you 🙂
Well done mate.
Thanks Mark!
Love the chicken action in the background
It does not work! The water will still get through dealing with issue now with the exact way he mentioned.
Adding some vents to your roof will also solve the problem
Adding roof vents will not help without a ceiling, creating a Closed attic area.
He would only lose what little heat he has in his shop.
Good job how sore was you the next day?
Not too bad... but now I know why my shoulders are stiffer than usual! LOL I forgot I did this yesterday! 😜
@@Samcraftcom 👍
That won’t stop condensation it’s just going to reroute and trap water. You’ll see corrosion, just a matter of time. Temperature in garage is Still lower than outside temperature. You’ve got gaps between foam and metal
Awesome Chanel!
Thanks!
Ohhh man its dont way out, you must do some Hydro barrier
Thanks for video..helped me right out. as I'm having exactly same issue.. thank you!
The foil will give you a lot better reflectivity with an air gap ultimately I have mine in my house underneath the trusses so I have 3 and 1/2 in I've lowered the temperature in a single story home almost 55°, the hottest temperature my house attic got last year could have a wireless smaller was 112° in Georgia pretty impressive I love me some The shield but she got to have the air gap if it's the hered directly to the phone board it doesn't work but only a tenth of %. You don't believe me it's actually printed on the phone board on some of them and those readings come from Ashare the people that do all air conditioning regulations.
All and all good video
Not good ideal reason the water will now hold ontop the sheets going into the wood and intime will destroy the wood,,, Just a word to let you know
If done properly like I show, no water will get in the area.
@@Samcraftcom It still has to have sweating thats what metal does when temps fall or rains all this does is direct it to another spot example wood that in time will decay , This is good ideal to rerun water to a drip point but it does not stop sweating , all tin will do it even a carport
@@kevinramey4226 the insulation board prevents the large temperature difference touching the metal which prevents the condensation in the first place.
@@tennesseetexan1957 No it doesn't it is till their you just hide it and if you check you will see it because lack of air will trap it inside
@@kevinramey4226 ok, so I guess if you spray foam it then you have the same problem?
Sam...are you on facebook...would love to chat some on this topic.
I am, here's my link: facebook.com/samcraftcom Thanks!
You should race your chickens. They are FAST!
You should have had your commentary voice over the video. The camera is too far away to see exactly what you are doing.
NOT GOOD AT ALL. That’s actually the Rich Mans way to do it. The wooden trusses are probably all absorbing the moisture now. They WILL ROT over time. Eventually the steel roof will start loosening up, leaking more and one day blow right off. At that point it will cost you a fortune. You need a vapor barrier between the lumber and the steel.
Yeah... don't do this.
You will create a sealed pocket of air and moisture.
Well, now you have closed the spaces, to the outside, at the top and bottom of the roof panels, where is your accumulated humidity going to go?
Accumulated humidity is not good for your materials, tools or green wood you are trying to dry.
I know i am stating the obvious but I do that because I often miss the obvious.
I know you did this at your old house but you didn't stay there long enough, to see the long term results.
You really should have installed a ceiling, with insulation and vapor barrier. That way you would have a properly ventilated attic space and no condensation.
The original build, of the building was as a shed, not a workspace. When you are working in there, you sweat and all your wood is giving off moisture, as well, even in the winter.
It has to go somewhere, but now it can't.
You're right! I plan to add a vent with fan at the top of the ceiling.
Do not do this. Water is sitting ontop of the insulation and will rot the wood ceiling framing 10x faster. Horrible Horrible idea.
Thumbs up
Thanks Duane!
Poor man's technique? Awesome! I'm poor! : )
:)
All you did was to conceal the condensation between the metal and the foam. I think you also said to use any construction adhesive for the foam. Can't do that. Any adhesive must be approved for the type of foam board used. Others will eat the foam.
He yaps for 3:15 mins. before he demonstrates if.
Thank goodness you were here.
I respect your knowledge but this video is far from a beginners guide..
No explanation, nothing but a fast forward video of you doing who knows what!?
Thankyou very much.