Vapor barrier seal

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Jwinston

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Hello,


I have a question about basement vapor barrier. My home is 2 years old. Basement is pored concrete and the builder has insulated everything. A few days ago I noticed that the plastic membrane is not tightly attached at the floor, maybe the caulking sealant is coming off. I attached 2 pictures. My concern is, does the vapor barrier has to be air tight? is it even possible? or is it normal to have some open areas?

Thank you,

Vapor barrier.jpg
 

kok328

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should be air tight with taped seams.
if you have enough length, run a bead of silicone on the floor and press the flap into the silicon.
 

nealtw

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Hello,


I have a question about basement vapor barrier. My home is 2 years old. Basement is pored concrete and the builder has insulated everything. A few days ago I noticed that the plastic membrane is not tightly attached at the floor, maybe the caulking sealant is coming off. I attached 2 pictures. My concern is, does the vapor barrier has to be air tight? is it even possible? or is it normal to have some open areas?

Thank you,
You must be in Canada?
Yes it should be completely sealed.
 

Jwinston

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Yes. I live in Canada. What kind of product can I use to seal the plastic at the bases? Is it some kind of caulking? My one year Tarion is not over yet. Maybe this is something the builder can fix.
 

kok328

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Yes. I live in Canada. What kind of product can I use to seal the plastic at the bases? Is it some kind of caulking? My one year Tarion is not over yet. Maybe this is something the builder can fix.
Silicon or a product called Quad available at big box stores.
 

Jwinston

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Hello guys. Yesterday I noticed light condensation in the basement corner, right behind the base stud between the floor and the wall. What do you guys think? is thins a common occurrence? I took a pic behind the stud, right at the junction between the floor and the wall.

condensation .jpg
 

nealtw

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If you have air leaks that allow warm moist air to get behind the insulation and contact cold concrete you will get condensation.
Tape a square of sheet plastic to the the area in question. moisture on the surface of that plastic would be condensation, moisture on the backside would be coming thru the concrete.
 

slownsteady

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Following up on Neal's suggestion; you tape the square of plastic to the concrete wall. Tape all four sides.
 

Jwinston

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Thanks nealtw and slownsteady. The vapor does appear on the backside of the plastic. So it seems to come from the outside. Do you think that maybe I should open that area and let it dry out? Is this a common occurrence?
 

nealtw

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Thanks nealtw and slownsteady. The vapor does appear on the backside of the plastic. So it seems to come from the outside. Do you think that maybe I should open that area and let it dry out? Is this a common occurrence?
Water does not usually leak thru solid concrete but it will wick thru it from cold to warm.
 

stadry

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barrier tape's usually used by pro's - we buy ours on eBay
 

stadry

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on walls, we use nailed-on p/t'd 1x2's for termination strips
 
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