Shannon's the man! Your videos have been super helpful throughout every step of a cold room conversion that I've been doing! So grateful for your videos!
Yes the moisture barrier is only used below grade and it is installed against the inside of the concrete wall. The vapour barrier is installed on the warm side of the wall, that is after the insulation but before the sheet rock. California may be different because of your warm temps all year, and the fact that the interior of your homes would usually be cooler than the exterior while running the A/C.
Yeah I see your point too ..thanks for your reply. interesting to hear the differences between your local codes and UK regs... thanks and Merry Christmas !!
Yes it really can cause problems sometimes but it meets minimum code where required. What i actually folded upwards was the flap from the moisture barrier and then taped it to the face of the vapour barrier . I could have cut both off at the floor and used acoustical caulk to seal the bottom but I hate that stuff it usually ends up making a mess. The best moisture barrier technique is to use styrofoam against the concrete ,it pretty much eliminates the moisture problems .See my video.
how do you stay motivated to keep making these videos and putting so much effort into them with all these negative mother in laws on here? good job sir i love your videos!
I did energy test on home for years. You can have a plastic against the concrete to stop moisture come trough the concrete. If you are really worried about it then don't do all the concrete, just about a foot above out side ground level. The biggest thing with any wall is not letting warm moist air meet cold because that will create vapor or dew. I personally like to fill 100% of the void between studs etc.. Tip of the day: Air is not a insulation and heat don't rise it moves toward cold.
+HouseImprovements Actually air is the insulator in fibreglass batt insulation. The loosely bound fibres create tiny little air pockets that are the actual insulation but because the pockets are small, there are no convection currents to transfer heat. That is why it is important to keep the insulation puffed up. Squashed insulation does not have the air pockets and the fibreglass itself is a very poor insulator.
+Mike from Enderby True but only if the air is stagnant (don't move). Once the air is able to pass through it and take the heat with it. I have seen people try to make a insulated wall by having it have it 1/2 air space 1/2 insulation. They are better of with 100% insulation.
So wrong you never poly both sides of the wall it makes it sweat box inside you leave a 1 inch gap between your concrete and frost walls and polly one side
Don't use a vapor barrier (plastic) in cold climates. This will trap moisture. DO use rigid foam board (XPS) against the concrete for a thermal break. If you don't use pink or blue foam board the studs are installed against concrete. All that outside hot and cold is conducted to the inside and it will sweat. When the wall is not supporting the house above, 24" on center gives you more insulation, less wood, better R-value. Encapsulate fiberglass insulation on all sides to improve performance
Nice job, and the comments are very educational on vapor barriers. No one really understands vapor barriers, even PHD's who study it. However, it takes warm moist air to hit a cold surface to create water (or just cooling warm moist air). Since you did such a good job of keeping any air flow out of the insulation, I would not be surprised if it worked well. It looks like a high-risk approach, but the way it is done makes sense. You will have moisture coming in from the concrete wall, but if it does condense, it will be blocked by the poly. This assumes a pretty well sealed and drained foundation. The inside poly will keep the moist heated air from getting into the insulation. The wall could stay nice and dry, if all else is good. I guess the important point is that if water gets into the wall, it will never leave, and the bottom sill will likely rot. So, if someone does this approach, there is no room for poor implementation. However, basements will always be a big challenge if you have water and organic materials.
I am an architecture student just wanted to say thank you for posting this video. Its great to see how the pros do it. Its a lot completely different experience when drawing plan on a computer. It has been very informative. Your Awesome Shannon and your camera people and video makers to. :) What are the differences between Moisture ans vapor barriers? Is a vapor barrier always required in exterior walls?
You make great videos. As a consultant I learn alot from your vids and its great seeing how you put things together. I think this may have been mentioned... but I don't feel good about that poly being folded up. Assuming the poly now encapsulaates the 2x4 on both sides.. the "built in moisture" has no where to run. in the winter time and with temperature drop in basement, this might cause some condensing... and moisture pool along areas of the wood.
Really appreciate your videos. They've helped me a lot with finishing my basement. Can you show an example of when a cavity between studs is slightly larger than the width of your insulation? I assume you just cut two pieces to fit?
All concrete, whether it's cinder block or solid wall acts like a sponge, and no concrete is impervious to water. To check this, do a patch test on a concrete wall. Tape a square of plastic on the wall for one week. After the week, take it off, and you will see moisture. Putting vapour/moisture barrier against a cement wall is a bad idea and is asking for mold growth. Owens-Corning recommends you never use batt products on a cement wall, only the above ground walls or knee walls. Always use a rigid insulation product on below grade cement, as it is mold resistant. You may not have a leak behind your wall today, but you may next year. Sorry, but I agree with D eez.
This system here is one that you can do ,and meets minimum code if you do insulate with batt insulation below grade against concrete. I agree that any concrete will let moisture through especially if not using damp proofing on the exterior, and even with the exterior damp proofing barriers if you do not have proper weeping tile in place you will have moisture wicking through eventually. The moisture barrier ( in this case poly) should never be sealed at the top so that the building can still breath to the outside like it is supposed to. I also agree with you and have other videos showing it, that you can use ridged foam against the concrete as insulation and moisture barrier. But that system will not keep moisture from wicking through the wall, but helps keep it from getting to your framing or batt insulation where mould likes to grow, just like the poly does in this video. Your primary moisture control should be from the exterior, in every basement.
I agree totally with your comment. batts never have a place against concrete, even with poly against concrete. the right way to do this is with rigid or with spray foam.
I could be wrong, but it does not look like the bottom plate is pressure treated lumber. Where I come from any lumber that rests on concrete must be pressure treated.
in the UK we would run cable in conduit and definitely not through any insulation. Because wires under load can overheat and break down the pvc insulation. Further we would probably run services behind the stud wall avoiding nails etc. Interesting to see how its done in your home town though ...
+MultiOutdoorman Most of North America does not require conduit in residential wiring, the electrical codes here are pretty strict on circuit loads to avoid overheating.
Thank you Shannon, you are very thorough and I appreciate the time you take to explain why and what you are doing. Where do I go to get on your forum? Thank you, Roberto
Never sandwich fiber glass insulation between two vapor barriers, especially in a basement. Open the wall in the basement 3-5 years later and you will have significant amount of mold on the cement and plastic. If you you want to use fiber glass insulation in the basement you should always install a Styrofoam 1.5-2" on the cement. Very important making sure it is flush on the cement and all joints are sealed or taped. Then you build your frame and insulate with a fiber glass insulation with a 6ml vapor barrier sealing all the joints and plugs. Now, this is the proper way to insulate a basement with fiber glass. That being said it is not the best way to insulate a basement by far. To prevent a damp, moldy basement and save money on energy cost, (also be much more comfortable) you should always use closed cell spray foam, urethane. It has a higher R value by inch and is also a vapor barrier. I recommend BASF Walltite
This is actually why the moisture barrier does not get sealed or go all the way to the top. Is this the best way...no. actually using house wrap as the moisture barrier is a better way. I prefer rigid foam against the concrete as a budget friendly better way to insulate basements.
In Canada we have very strict building codes regarding Insulation of homes. Being an insulation contractor with almost 20 years experience I've seen some nasty things in basements and attics. In our climate this is a receipt for mold. Spray foam is the most efficient and cost effective way to insulate any basement. In the long run it is cheaper then having to gut the basement have the mold professionally removed and then starting over.
This was Canada and was installed and inspected. I'm not saying it is the best way . Spray foam is great for those who can afford it but not everyone can.
We just purchased a house in Alaska, built in '75. The split-level home has a concrete slab floor. The first 3' is block, then 2x4 exterior walls. it currently has fiberglass insulation covered by poly on the block and 2x4's. Is that ok? We have found moisture problems in the lower level (when we pulled the carpet and baseboard), makes me think its not ok… Any suggestions.
Jon Hunt You are getting a moisture problem because the block section is not insulated at all so it would be getting some frost build up during the winter. The best thing to do would be to install at least 2" rigid foam insulation to the exterior of the block and then cover that with exterior finish material to match your home. Please use my forum if you have more questions in the future. www.house-improvements.com/forums/
These are great videos. Thank you. I have a question about drywalling in the basement. When you screw the drywall to the studs, don't you put holes through the vapour barrier, and ruin your air pocket?
i get the vapour barrier on the warm side, but why the moisture barrier on the cold side - wouldn't that trap condensation in between the two plastic sheets?
You should have shown how to do the inside corners as well. I guess I'll make a video showing how to do this as I cant find anything anywhere. Cheers :)
Question: All videos I see seem to be with new construction: What is you are starting with studs where as you have removed previous wood paneling and had no insulation behind it. Do I use foam board which I won't be able to tounge and grove because of the existing 2x4s or something else?
Good video shannon...When you are folding over the poly at the bottom, why can't you just tack it to the studs without taping it, since there are no air leaks between the overlap?
House as built basement walls studs floor to ceiling with front of studs 4" from concrete. tar paper on concrete fibreglass pink between studs all covered with vapor barrier. Need to have supply duct on outdside wall to "bathe outside wall". Not sure acceptable options to install supply duct and get maximum insulation. Std rect duct is 3.25" deep leaves only 0.75" for insulation which is less than r5. Is furring studs with 2x2 an options to build out wall
Great video. Thank you. Just to confirm, a moisture barrier is to be applied against the cement. Then your framed wall and insulation. And then a vapor barrier applied over that on the inside?
I can't see why thicker insulation would not work? How thick are your studs? If they are 3" you could Cut 1-1/2" or 2" insulation slightly smaller in width than what the studs are ,install it then use canned spray foam to fill in the gaps. If you really can only use 1" styro for some reason you could use two layers of 1/2"
Thanks for the video. I am wondering if the staples should be taped over too. Don't all those holes allow moisture vapour to get past the vapour barrier...and would it be worthwhile to put an inch or two of insulation covering the studs on the concrete wall too so you have a complete "wall" of insulation, or is the r-value of the studs sufficient?
Remember, its not the fiberglass that insulates your wall cavity, its the air that it traps. When you compress insulation that's larger than the cavity space, you are not "adding" R-value, in fact you are removing the precious air space by doing this. So today, we have R21 insulation for 2x6 walls, if you compress this in a 2x4 cavity, you're only getting R13 and wasting your material costs away. www2.owenscorning.com/literature/pdfs/10017857%20Building%20Insul%20Compressed%20R-Value%20Chart%20Tech%20Bulletin.pdf
I have put in fiberglass batt insulation in between the floor joists for a raised enclosed porch. The floor of the porch is about 2ft off the ground, and because the vinyl siding of the porch does not go all the way to the ground there is some exposure. I don't think the elements would effect the small amount of exposure, but should I put poly plastic over the insulation?
What happen if my dad use the square box frame style put up the frame and forgot about insulation and plastic barrier.. the basement have complete almost 10 years ago. Do I have to redo and add 2 materials inside into the drywall ?
Ok so my question is, I have a basement that gets water I put ugl on the wall and a beaver system rather than adding a French drain. The water only occurs in large storms like 5-7 in rain falls. So I am insulating my basement should I put the vapor barrier before the insulation to protect it from getting wet or should I do half and half so top portion put the vapor barrier on the outside of insulation and bottom half wall put it before insulation?
Is it possible to install a thinner batting to put between 2x6's so that I can hang drywall on the same studs? I'm converting a garage into an extra room.
You know, if you took a knife and cut a slit halfway through the insulation at the height of that wire you could insulate around that wire without having to pull every piece apart sending so many shards of fiberglass into the air! It would also help to keep the insulation from settling so much over time which it already looks like that fiberglass really wants to do!
The method you are referring to is called "filleting" and is generally the way I prefer to do it also. I am not sure the end result is much different, but I agree it is a little more precise, faster, and just not as messy.
Correction: you should emphasize that it IS very important to wear the mask, and eye protection also. Those fibres are inorganic and small enough to get lodged in the lungs. ask any old insulator.
We have an old house and tore the wall down to reinsult. We put in the insulation and vapour barrier. The wall is sweating on the inside of the vapour barrier, any ideas what the issue may be?
All that insulation seems a little excessive. I live in Florida and I want to put up drywall on the cinder block wall. Does anyone know how much insulation I would need to put up or what type?
I have a basement wall (poured concrete) where I had to repair a foundation crack. Only a small section (6' x 8') of the drywall, insulation & vapour barrier had to be removed. Can I not just lay the new insulation bats directly on the concrete and add the new vapour barrier on top before fastening the new drywall? I see in the video, a plastic sheet on the concrete.
You should have a moisture barrier between the two. but if the rest of your house has not got it then a small section wont make much difference anyways.
how do you install vapor barrier / insulation if you have 3 basement walls that are all concrete blocks floor to ceiling and the 4th wall leads into crawlspace with dirt floor and moisture is a problem in the crawlspace. the basement walls are half in above ground.
I studied carpentry in canada last year and basement insulation was only "concrete-glass fiber batt touching the concrete- Studs at 1" offset from concrete -vapor barrier 0.006"- gypsum pannel What is the purpose of your first "open/untaped" vapor barrier
Thank you Shannon for your great videos. Do i get these materials on my local stores like Home Depot or Rona or are there speciality store where i can get these ?
One of the first houses I built with pink batts in the walls required plastic lining on the studs over the pink batts and under the gibboard.This was not a good Idea as the walls built up a lot of condensation. Needless to say the council soon changed it's policy on the addition of plastic in the walls and I might add it was on timber weather boards.
Thx for the very useful videos! Do you recommend products such as reflective multifoil (radian & vapor barrier) for wall / floor / roof insulation in wood construction, instead of fiberglass? Thx for your answer.
Shannon, I have a wall I like this in my finished basement that is currently framed out and dry walled with a ledge. I am planning on re-framing the wall so that it is flat from floor to ceiling for the installation of a kitchen. How do I join the vapour barrier I will install on my new wall to the existing vapour barrier that is behind the drywall on the adjacent wall in the corner and keep a good seal. They are both exterior walls.
If you are not exposing the side wall then all you can do is seal the new vapour barrier directly to the drywall face in the corner where the new drywall will cover it.
My home basement wall comes with an R12 fiberglass with Vapor barrier all the way down the floor. To finish the basement, do I need to bring up the R value to R20,(I am in Canada) ? If I do want to bring up to R20, could I add framing studs around the existing insulation and add another layer of fiberglass batt between the studs ?
i've seen those 6mil poly barriers seal in and trap moisture/ condensation, and create a green house effect..is this really a good idea Shannon? mostly, I've witnessed this happen more in sub-area's
The series of moisture and vapor barriers you've got going on here is pretty confusing. Not to mention the comments about them. In California, (I think) the moisture barrier goes on the cold side of the wall. Ok, now I'm thinking that's the vapor barrier. Man... Ok, yeah, the vapor barrier goes on the cold side of the wall so that'd be Tyvek on the outside of my exterior wall studs, then insulation and then sheet rock? The moisture barrier is only for the subgrade walls right?You used both here?
also...IMHO shouldn't that INTERIOR vapour membrane be laid top first and work down (unlike the exterior) so any vapour can run onto the sections beneath and not down the wall ?
why is the vapor barrier installed right against the foundation. I thought it goes only on once the framing and fiberglass insulation is installed? please explain.
HouseImprovements but you have 2 vapor barriers installed. One right against the foundation wall, and then another one after the fiberglass insulation? Why do u use 2? Many online forums that I read say that vapor barrier should not go right against the foundation wall. I'm just so confused, that I don't know which is the right method.
My basement walls are covered with r8 insulation and a membrane from the very top to the middle of the basement wall. Upper part. Approximately 60 % of basement walls area are covered, ~ 3 feet lower than the ground level. Ontario. Can I just frame it and go further, or I need to cover the lower part with insulation and membrane? Thank you in advance.
How do you feel about vapor barrier in north Texas? I’m conflicted since there seems to be arguments from both sides. Some say it actually increases your chances of mold. I’m really confused. Thanks.
At the bottom Vapor Barrier would you leave the excess out if you install subfloor? Do you want your Vapor barrier tight up with your subfloor. For bassement...
Hi, I'm doing a chicken coop and I was wondering if I should use a Vapor barrier?The coop is not heated.Just repairing the outside wall and putting in some insulation.
LeabKnott Yeah...it is called a sill gasket ;) You MUST use it or you're gonna have rotting sill plates in no time! If you don't use sill gaskets, you can use pressure treated lumber, but it's illegal in Canada to use PTL indoors. And don't use nails to secure the sills. Use tapcon screws. They won't rust!
im completely redoing a very old trailer, the walls are 3 inches thick, i need to replace all the paneling, insulation and boards. i was told that i have to use 1 inch insulation, but i cant find 1 inch insulation any where, is there something else i can use instead or maybe tips for making 1 1/2 inch insulation work? keeping in mind i live in western montana where it does get cold. ill also be using a wood stove as my main heat source. thank you!
Hey Shannon, your videos are really useful and easy to follow. I have a question for you. I am topping up the insulation in my attic and I realized there is no vapour barrier under it. Before I add more insulation, do you think I should move the insulation I already have and add the vapour barrier? It is loose fill insulation and about 2" deep. We are in Ontario, Canada. Any help would be greatly appreciated.
Christofer Espinoza Drywall, when painted, acts like some sort of vapor barrier. Condensation doesn't happen when hot meets cold. It happends when there is moisture either in the warm air or cold air. You will see condensation forming on concrete basement wall because there is always moisture getting through the concrete, since concrete is never 100% waterproof! Since painted drywall acts like a vapor barrier, it keeps most of the moisture inside the home. And btw, if there is a shinny finish visible on the face of the drywall (under the insulation in the attic), that's a vapor barrier!
+John Lomurno and we have to be off the wall 5-6" to hide some pipes so, not sure about creating the space in the wall, does it all have to filled with insulation?
+John Lomurno Yes you will need a moisture barrier against the concrete (poly or house wrap will work). Then you need an air/vapour barrier between the studs and drywall.
John Lomurno Isn’t the primary purpose of vapor barrier to prevent condensation that occurs when warm moist air meets cold air from getting into the insulation? Isn’t it a fact that condensation will occur whether you have a barrier or not so the question is really where do you want it to be contained? If warm moist air from inside the home is the source of condensation wouldnt a vapor barrier behind the sheet rock keep it out of the wall and insulation? So why the need for vapor barrier on the outside of the studs (or on the inside of a concrete wall) necessary?
You should NEVER install fiberglass insulation over concrete even if you put a vapor barrier over concrete because you're trapping moisture in between the poly and the concrete! Since concrete is not a vapour barrier, any condensation (and there will be condensation!) that gets between the poly and the concrete will drip down the floor and rot the sills. Since the air inside the wall cavity is at the same temperature as the air between the concrete and the poly, there will be condensation forming into the fiberglass as well! It will end up rotting the studs! Instead, put styrofoam (which is a vapor barrier) directly in contact with the concrete, and put wood strapping (1x3) over it. Styrofoam is a much better insulation than fiberglass and acts as an air barrier AND a vapor barrier! It takes one third of the time to put it up compared to all the steps described in this video. Anyway, fiberglass should never be used for insulation except for above ground applications.
steevemachine This actually completely meets code. The poly against the wall is the moisture barrier and will direct any moisture that comes through or forms on the inside of the concrete to the floor .Because the moisture barrier is under the bottom sill plate the wood is not in contact with that moisture. As long as you do a good job sealing your air/vapour barrier that prevents moisture from getting in the actual wall cavity and causing moisture problems. I do agree that sprayfoam or rigid foam is a better choice and better system but this video does actually show minimum code requirements.
HouseImprovements Actually it's against code in Canada! You're trapping moisture between both vapour barriers! It'll soak the batt insulation over time. One sigle hole the size on a pen tip in a vapour barrier will let in the equivalent of a cup of water into the batt insulation over the course of one season. Since an above ground wall can breath, it's not that dramatic. But in a basement, it's different! It can turn into a lot of mold problems! I really appreciate the fact that you take time to explain all this, but since we all know that minimum code sucks pretty bad, why not just do the right thing first? We all know that it take a lot less time and hassle to just put rigid foam on the wall and install wood strapping over it! This way you don't have to worry about a moisture barrier or a vapor barrier! Keep up the good job!
Do I need a vapor barrier in my basement if Im using roxul between the wood then hang a vapor barrier? Or Could I use spray roam or rigid without the vapor barrier?
Rigid foam is really expensive.Could a guy just put 1/2 r3 foam around perimeter of foundation walls,place framing up,then install batt in between studs to bring r value up for the room then drywall?no poly needed if the foam is a vapor barrier?
16 inches would mean you are making two runs of screws down the ~center of the drywall. Basically two studs backing each piece of Sheetrock. 48 inches per sheet and 16 inch spacing on studs gives 2 plus .5 a stud plus .5 stud. 24 inch spacing leaves one stud per piece of sheet rock instead of two, right down the middle. 16 inch is more sturdy, but these walls are backed by concrete so that may be why he chose to do 24. If it is standing alone and exposed on both sides, then 16 inch spacing would be safer and more sturdy.
