Vapor barrier and Drywall issue

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Posted by: from Vancouver
2/12/2020 at 5:15:01 AM

Hi, I had a question regarding Vapor barrier. I had a renovation to my kitchen last year and the electrician had cut a long section of drywall to run wires for undermount lighting.

He didn't tape the Vapor barrier back together and the cabinet guys installed the cabinets over the drywall without mudding that section back into place, would this be an issue for moisture down the road and is this something I should be concerned with?

Inside the cabinet is reading about 4-5 degrees colder than the other part of the kitchen,

This is on an exterior wall.

Also the bedroom that's directly below the kitchen has begun to have an earthy smell to it, I've inspected the entire room for mold but nothing shows up and my moisture meter is showing 0%

This would be quite an extensive repair as it would require me to remove my entire kitchen and wanted to check before I began such a large repair.

Thank you for your time.

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Date/Time2/12/2020 at 2:11:28 PM

Than k you for your excellent question.

This is absolutely an issue because it is an exterior wall.

Moisture from the interior of the house will be condensing in the insulation and the cold area within the wall, and likely creating that smell in the chamber below.

The electrician has broken the vapour integrity of the build, and he should know better.

Was he even a licensed electrician? If he was, I would first pursue getting him back or having him pay to correctly repair the barrier. If he will not, advise that you intend to report him to the province.

As for the drywall itself, less of a concern, as drywall is a fire separation, primarily, though done correctly, it would have been patched, providing another degree of isolation to the vapour, depending on the drywall type used.

As for the vapour issue, it likely won't get better on its own.

The electrician is responsible, here, and it should be addressed.

I hope this works out for you,


Director of Operations

Pierwater Custom Construction Ltd

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Date/Time2/12/2020 at 2:37:41 PM

Earthy smell your smelling in your house. Depending Whether your house is New or Old it's a good chance. That's mold. And as far as your kitchen, you should be fine.

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Date/Time2/12/2020 at 6:28:31 PM

To be honest that's a tricky situation they definitely should have overlapped the vapour barrier and taped it because there is a chance of moisture I would go up in the attic if possible and see if he can do anything up in there unless it's is in a bulkhead but I would honestly try an attack this from the attic if possible. I'm not sure that is an option for you

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Date/Time2/12/2020 at 11:56:59 PM

The answer is Yes! The vapor barrier is a essential point in the wall structure. It is a moisture as well as a air barrier. The cold side of the vapor barrier is the due point in the wall and if your wall structure has been build to building code, it vents to the exterior of the home. Now you have a breach in that permitting moisture as well as air (cold) to inside. The end result is that over time this moisture does not have a chance to dry properly and we all know what that means! Mold begins to grow! and the smell is a indication that this has already began!This is a great example of what not to do! covering a problem does not make it go away! often sub-contractors will deem its not their responsibility. However not doing your due-diligence puts the liability on both the electrician for not correcting the breach and the cabinet installers who ignored the obvious issue and covered it up! Two wrongs do not make a right! Also as far as your basement is concerned. I do not believe this is a result of the breach above as the vapor barrier is sealed at each floor top and bottom with acoustical sealant! For this issue I would suspect it being a air movement issue! stagnant air needs to be addressed by circulation. And the movement of air inside your building envelope. Passive air systems often lead to this problem! The remedy is to have air flow throughout your home as this help dry out any condensation that accumulates due to our climate.

Hope this helps in the understanding of our building practices.

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Date/Time2/13/2020 at 12:30:48 AM

Hi Han,

Unfortunately there is no way around this and the issue MUST be rectified or you are definitely at risk for mold issues etc etc.

Sounds like some previous trades are liable & I would pursue them to cover costs!

Best of luck....

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