Thanks. I'm leaning towards not using vapor barrier to allow the garage to breathe - but am concerned this will diminish the effectiveness of the insulation. I plan on having a small heat source in there 50% of the time.there's varying thoughts on vapour barrier in garages in our climate
either way will be fine IMO
I'm thinking of insulating my new garage which will only be heated some of the time. I live in a cold climate (Canada). Should I put 6 ml vapor barrier between the studs and the drywall? (drywall is required to meet building code for fire protection).
Will installing a vapor barrier cause a mold problem?
Wow, so the drywall is "reused" now?
I would not have done that unless you have some kind of water vapor producing "thing". Like a pool, group of people inside, shower, unvented heater, etc. I suppose a propane forklift could also do it if you ran it inside a lot.
Or a car with snow and ice melting off.
Wow, so the drywall is "reused" now?
I would not have done that unless you have some kind of water vapor producing "thing". Like a pool, group of people inside, shower, unvented heater, etc. I suppose a propane forklift could also do it if you ran it inside a lot.
Or a car with snow and ice melting off.
I'm up here in Canada too in the same situation, no vapor barrier here...it's just going to hold the excessive moisture from melting vehicles in even more. Plus, primed/painted drywall can in itself act as a pretty substantial vapor barrier.
If the garage is insulated but usually unheated, no vapor barrier...if the space is always heated, then yes vapor barrier. That's what the permits for my attached garage required here.Absolutely not lol there is no point in insulating without a vapour barrier. ESP with heat. If you have heat then I suggest you pull some insulation out and look at the frost. I wouldn’t build without it an no one who knows what they are doing should.
There is code on vapour barrier required. I believe it states thickness? Common is 6mil cgsb poly. Exterior foam is aloud I think if it’s thick enough to maintain a temperature on the inside face to not cause condensation.
If the garage is insulated but usually unheated, no vapor barrier...if the space is always heated, then yes vapor barrier. That's what the permits for my attached garage required here.
Garage space does not match living space from a code perspective.
Is the VB still needed if you are not dry walling? I plan to put up OSB and I don't plan it to be airtight either.
In Canada, the outside relative humidity is low. Chances are, there will be more humidity in the garage....so I would put the VB on the side between the drywall and insulation.
What about the Insulation that has Kraft paper on it? Isn't that considered a Vapor Barrier? If you buy a Garage Kit from a Box Store they don't include Vapor Barrier. Do they assume that the Kraft paper is the Vapor Barrier?
You'll find it touted as such, and it is better than nothing, but not by very much. Visqueeen is both cheap and far easier to instal properly than Kraft-faced insulation.
That kraft faced insulation has no place in walls that actually need insulation. Some people seem to think of something claims it can do something they are ok with that. Even though it does it poorly or not at all. Doing something half way in building is almost always worse than not doing it at all.
About the only place it's useful is in overhead installations, where stapling it to the rafters helps keep it from falling out. At least until you can come back and install the visqueen and sheathing.
The use of plastic VB should be avoided in almost every case .... the key to good buildings is to air seal. The movement of air is the main driver of moister into a wall ... with no air path the water movement is so low that anything will dry.
Plastic VB will trap moisture -- very bad. Just because you see something all the time .. does not make it correct. I'm always making comments about not venting .. it's the same thing/idea ... we have been doing things now for a couple generations. But, it's not based on sound science ... it's .. well we always did it that way.
do a google search -- and see those homes with early mold and wall failures ... plastic is the problem. In humid areas -- it's the wall ... in dryer areas it's the backside of the drywall.
Batt type insulations -- even Roxul will allow air movement. If you install plastic -- you run the risk of trapping that moisture. Paper VB retards air movement -- and moisture movement but it does not stop moisture movement .. so the wall can still dry to both the inside and outside.
Plastic .... should be used under a slab .. that's about it.
Completely wrong. There is a reason it is code. The poly does not trap moisture when there is no vapour barrier on the outside of the wall. Your theory is crazy. Why would Vb produce mold? When you seal a house you also need to install a proper hrv system to replace the inside air with fresh air. A hrv is also code and must be installed on new houses.
Your first sentence baffles me. You say plastic vb should be avoided and then follow it by you must stop air movement....which is what the poly does. I don’t even know why I would reply to your post but it seems like you don’t know how good building practices are. You vent on the outside to keep the air flow and avoid moisture build up and you seal inside to keep the warm air from condensing and causing moisture inside a wall. I hope you are not a builder and are advising people the way you seem to think stuff should be built.
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You absolutely need to use vapour barrier. I'm just in Richmond hill and just finished tearing out all the drywall the previous owner installed. the garage was very damp in the winter from melting snow, and the drywall was sagging from the moisture it absorbed. The garage was fully insulated with fiberglass insulation some of which I had to replace because of black mold, further, the garage roof was leaking in two places which made things even worse !. I'm just in process of putting in vapour barrier now and will start installing new drywall in about a week.
I know what i speak .. do some research before you say someone is wrong.
It's not hard to find the facts. Mold has become a problem because people keep using impermeable barriers.
The whole reason for the development of house wrap was to sold the air problem and still be able to use inexpensive fiberglass batts.
venting and plastic are bad bad bad ... Have not done either in over 30 years. Foam is the best with proper positive fresh air intake .. but a good building can be done with batts ... not with plastic.
exterior water intrusion will add huge amounts of moisture -- w/o air movement the amount of water that get transferred through drywall in a garage is minimal .. A structure will dry from both sides .. that's why house wrap was developed.
A leaking roof would cause even more issues with plastic VB.
Do a google search on the subject -- there have ben recent studies.