# Vapour barrier at basement window help



## johnvosh (Jan 5, 2014)

I'm hoping I have this in the correct forum. Anyways, check out the attached pictures. How would you recommend I fix this? This is how the builder left it! I also can't believe how they concreted the basement window in. It's going to be fun to try and finish this window nice. The air & water that's going to get into the insulation will be crazy if I don't fix it before the spring thaw.


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## Windows on Wash (Aug 30, 2011)

Nothing different or incorrect about that basement window. The windows are normally cast in the basement walls as the frames are part of the wall forms.

Adding jamb extensions and trim is no big deal.

Prior to finishing off the basement, I would really read up on insulation strategies and make sure that you have a well thought out and developed plan. 

You only get to do it one correct.


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## johnvosh (Jan 5, 2014)

The insulation that is in the basement is on either end, pink insulation and vapour airier that the builder installed. On the side with window, I've already used tuck tape n at least half a dozen holes they left in the plastic.

I'm just kind of wondering where I should tape to around the window to fix the horrible job they did.

As for the rest of the basement walls, I'm an inside unit of a 4-unit townhome. I plan on using roxul as the walls are already studded, 24" on centre, mainly just to act as a sound barrier. Do I need vapour barrier?


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## michelclarke (Oct 26, 2013)

I only have the privilege of working in old basements, exterior treatments are not an option. Most times, French drains are already installed. I will not work in basements that have water issues. If I smell dank air, I advise on seeking a waterproofing contractor first, remedy the situation and then call me.

This is going to be a lesson for me...Let me keep asking since I'm getting good answers. Sometimes an old dog needs to learn a new trick!

Is the rigid insulation you are talking about blue board that's about 1" thick? I think I have seen it in 15" wide strips that fit in stud bays. Do you frame first, then insulate or insulate and frame in front of it?


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## Gary in WA (Mar 11, 2009)

So is there just the layer of poly next to the drywall?

http://www.buildingscience.com/docu...Hygrothermal_Modeling_Basement_Insulation.pdf

ftp://ftp.cmhc-schl.gc.ca/chic-ccdh...ngual/Vapour_Permeance_Volume_1_Web_sept5.pdf

The actual test; http://www.google.com/url?sa=t&rct=...sg=AFQjCNHOYZUsY1yGogCyU94l00Ph3dQqtw&cad=rja

"As for the rest of the basement walls, I'm an inside unit of a 4-unit townhome. I plan on using roxul as the walls are already studded, 24" on centre, mainly just to act as a sound barrier. Do I need vapour barrier? "---------- no, there is a conditioned space on the other side, it doesn't even require insulation other than for sound- even then- 8" concrete.....lol.

Gary


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## johnvosh (Jan 5, 2014)

Gary in WA said:


> So is there just the layer of poly next to the drywall?
> 
> Gary


Right now there is no drywall on any wall in the basement. They came with unfinished basements with just a studded wall/insulation/vapour barrier on the two outside walls. Heck, they only put 1 outlet in, at the panel for the entire basement! And all 3 of the pull string lights which were plastic had to be replaced as they were all cracked and didn't work very good!


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## TotalHomeworx (Jan 18, 2014)

That's pretty standard. You can use "acoustic seal" instead of tape to attach the poly to the concrete at window area or use spray foam. 

Builders usually just throw in some studs and insulation and say "it just needs drywall" but it's just a way to up sell the home. They builder has to insulate the exterior wall anyway and just throws up the interior framing. Usually its all the left over studs that are all warped and twisted.


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## michelclarke (Oct 26, 2013)

Polyurethane sheeting is a typical vapor barrier that contractors use to prevent moisture from penetrating the walls of a basement. The material is stapled to the frame of a basement wall before it is finished with plaster or drywall. A vapor barrier is also helpful to keeping a basement insulated and warm.


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