Do Peel & Stick Membranes Trap Moisture?

[@librespenseurs2945]

I am a house designer in Quebec (Architectural technologist). I have a lot of experience in construction details, both in new construction and retrofit. your videos give me a useful second opinion when I'm not convinced about the soundness of my concepts.

[@justforyt]

I just wanted to say I absolutely love your channel and the information you put out. I repost a lot of your videos. I know youre not getting a ton of viewership yet. Please keep it up. This is great content and I'm sure you will continue to grow.

[@cw6410]

Great video to show your workers so they understand what they are doing

[@ChristopherCurtis]

Great video. The BS+Beer show talking about "vapor barriers" with Steve Baczek just released yesterday as well. I only half paid attention but it sounds like the easy answer is avoid *barriers* (everything needs to dry) and watch out for microclimates. They mostly talked about poly though, not peel-n-sticks specifically.

[@ASIRIDesigns]

100%. You have to be extremely strategic when it comes to vapor *barriers*.

[@WhiteytheLab]

I know, right? At first I thought I was supposed to seal my buried concrete footings/ walls from water infiltration by using the black asphalt sealant. Now, I may just be trapping the water to the interior. I also considered a Xypex concrete additive to make the concrete itself waterproof from inside. Seems the tighter we make these buildings, the more moisture problems we have. I'm considering just having a poured concrete wall, 2-inch thk rigid Rockwool (which breathes), and a rainscreen like brick or hung slate tiles (CupaClad). I thought I was supposed to use a water sealant to protect windows and openings from any water that gets past the rain screen, but now I just don't know...

[@ChristopherCurtis]

@@WhiteytheLab Interesting. This is a learning process for me as well. My takeaway from all I've gathered so far is that concrete is always wet, and it is going to dry to the inside, and that's okay. If you want to try to block vapor/moisture, the primary barrier goes on the outside (asphalt/drain mat on the walls; crushed stone on the underside). Next is your insulation (EPS - it has to be ground contact rated; XPS/Polyiso are no good wet). Then consider your vapor barrier: immediately below the slab continuous to the interior concrete wall. This will hold all the moisture inside the wall. It will try to dry to the uncoated above-ground exterior or if you are using ICF up through your sill. Make sure you use a gasket or sill seal so you don't have wood on wet (concrete). If you _don't_ have a vapor barrier on the interior it will dry to there. What you don't want to do is frame or insulate and put the barrier somewhere else because the water is mostly in the wall, not in the air. If you wanted to add another vapor barrier for whatever reason (and you probably don't), use a vapor-variable membrane. I think ASIRI has mentioned manufacturers in other videos. The real problem with moisture (according to BS+Beer) is air. I'm making up numbers here, but vapor pressure will move something like 3 liters /day, while a 1" square air hole can move 30L/hr. Stopping air movement stops the vast majority of vapor movement. Anything above grade you're trying to stop bulk water, so yes, take lots of precautions there. Let gravity do its thing and always give water a way out and away so walls can dry.

[@WhiteytheLab]

@@ChristopherCurtis Thank you for taking the time to explain that for me. It is truly appreciated. It feels like the more I learn, the less I know (lol!) Thank you again! Actually, it's great information and will help my design considerations (and price estimates to know what to include...)

[@ChristopherCurtis]

Drying into the mudsill for ICF didn't make sense to me so I looked that up: If you have a vapor barrier going up the inside of the concrete wall, you want to tie it to the exterior WRB under the mudsill. The principle is the same though: keep wood off of wet. It appears that the situation is the same for exposed ICF: EPS is a Class II vapor retarder so moisture is still going to dry to the inside, albeit not as quickly as if the concrete were fully exposed. I wonder if anyone can answer a question about gaskets though: I've read that gaskets are better than sill seal, but if we're tying the vapor barrier to the external WRB, how are you sealing the gasket/sill-seal? Concrete->caulk->poly->caulk->top-plate makes sense to me as a barrier construction, but where would you add sill-seal or a gasket? Concrete->caulk->gasket/seal->caulk->poly->more-caulk->top-plate? Do you skip the more-caulk and assume that nobody will ever puncture the poly/vapor barrier?

[@justincarrasco3680]

Great video, as usual! I think vapor permeability and how it affects a building can be a pretty confusing topic at first, but your videos have really helped.

[@ASIRIDesigns]

I'm glad you found it helpful!

[@WhiteytheLab]

Had my roof replaced back in May. I was so pleased with the contractor for seemingly being in-the-know and getting the ice&water shield layer up there. After watching this video, now I'm all paranoid that it's just up there rotting my roof away (lol)... 1. If I do poured concrete walls (actually hate the styrofoam on ICFs), I was gonna do the black asphalt water sealant for the buried part of an integral footing, and I thought a peel-n-stick would keep any water that got through the rain screen from getting on the concrete. 2. Do you think Xypex admixtures or sealants have a good reputation to make concrete waterproof?

[@ASIRIDesigns]

@@WhiteytheLab No need to worry if the roof is vented. As for the cast in place concrete walls, it really depends on the assembly but when we are dealing with below grade conditions, we actually want the benefits of a vapor retarder since moisture is always trying to try to the interior. Drainage is more important than the waterproofing in this case in terms of keeping water out. We actually have a whole video on below grade waterproofing systems on our channel that we posted a few months ago.

[@WhiteytheLab]

@@ASIRIDesigns THANK YOU! My attic is so well vented I felt the ceilings lift when I got hit by a tornado 6-months ago (lol). Thus the severe desire for a concrete home, aye? I'll go find that below grade video... I'm assuming you folks are available to hire as consultants when I get to the design phase? (saw tyou had a 10-hour minimum, which was fine.)

[@matthewsicard5573]

I’m interested to know more about the impact of adding exterior rigid foam on the ability for the wall to dry outwards when using a vapour permeable SA membrane. Does the foam board installed tight to the SA WRB prevent drying? If so how important is it to use a SA WRB with an incorporated drainage plain (like Hydrogap SA)? I understand that rock wool would solve this potential problem but I’m trying to understand the best methods of using foam board on the exterior. Love your channel and the comprehensive information that you share! It’s an incredible resource.

[@GrampalettasCamp]

Great content and if you just added when/where to use each type, your education would be much more complete. Perhaps a follow up video

[@RealMrYouTube]

If moisture is accumulating in an attic space like that, there is an issue first with the venting. Ridge vents can get clogged or installed improperly which would prevent moisture laden air from being drawn out the vent.

[@2point..0]

As always I am still a little confused, ha ha ha!!! But I am learning from your great video's Liked#24 N Subscribed!!! Thank you for the informative videos keep them coming!!!

[@ASIRIDesigns]

Thanks for watching and subscribing!