Looking for answers to basement insulation fail

Ask your questions pertaining to the interior that don't fit in the above categories
Post Reply
Gaviness
Posts: 3
Joined: Tue Jan 01, 2019 8:28 pm

Looking for answers to basement insulation fail

Post by Gaviness » Tue Jan 01, 2019 9:11 pm

Image[/img]Hello,

My basement was finished by the previous owner and have often wondered if they did it correctly.

Today I ripped out some cabinetry, in an alcove that is 4ft deep and 10 feet wide, with a further bump out at the back of that which is 2ft deep and 4ft wide. The smaller bump Out supported a chimney that encased a wood stove on the main level ( this day outside the main house).The stove and chimney were demolished the block wall cavity was filled with insulation and a vapour barrier was installed on the warm side and the block wall bump out was capped with concrete and water proofed with xypex capillary sealer.
F5541BFF-3839-46F9-A428-1F77C25BA876.jpeg
F5541BFF-3839-46F9-A428-1F77C25BA876.jpeg (109.21 KiB) Viewed 90 times
CC36A985-B240-46C8-B629-E1223185BAB4.jpeg
CC36A985-B240-46C8-B629-E1223185BAB4.jpeg (138.24 KiB) Viewed 90 times
4C7AAFCB-2C31-4DFD-90AF-634D573459DE.jpeg
4C7AAFCB-2C31-4DFD-90AF-634D573459DE.jpeg (95.19 KiB) Viewed 90 times

Now that I have given background to the construction above ground, I will describe the method used in the basement.

The original builders vapour barrier plus 1 inch thick insulation that extends slightly below ground level was left in place. They framed on top of that, insulated and put in a vapour barrier. No accustical sealer nor tuck tape were used and outlets were not sealed in either.

I found significant condensation on top of the builders vapour barrier under the r12 pink insulation. The insulation was moist where it came into contact with the block wall. The builders insulation looks black in spots. There's a section of bottom plate that has dry rotted.

Was this a failure due to lack of proper Vapour barrier sealing?

What can I do now to remediate this small section?

Should I i put a moisture barrier like typar directly on to of the block wall and perhaps remove the builders insulation?

Please note I don't want to rip out the rest of the drywall and I managed to squeeze my hand into finished section and found it to be dry.

Hopefully this is all clear. Thanks Gavin


User avatar
Shannon
Posts: 11707
Joined: Fri Nov 25, 2011 11:58 pm
Location: Canada
Contact:

Re: Looking for answers to basement insulation fail

Post by Shannon » Wed Jan 02, 2019 7:54 am

Well there are a few issues here as is plainly evident ..No moisture barrier, missing insulation and un sealed vapour barrier to name the main ones.I will assume the entire basement was finished this way but at least for now you should do what you can to properly put this back together. Cut out the builders insulation and install a moisture barrier against the block wall. Then you can re insulate . Lastly installing and sealing a vapour barrier will get this area at least in better shape.
If you've found our videos or website information helpful, please considering pledging us on Patreon

Gaviness
Posts: 3
Joined: Tue Jan 01, 2019 8:28 pm

Re: Looking for answers to basement insulation fail

Post by Gaviness » Wed Jan 02, 2019 8:25 am

Thanks for the advice. You'll notice that there is no moisture barrier under the bottom plate. Should I foam under there prior to putting on the vapoorbarrier?

Note: it was me who took out the insulation and vapor barrier when I ripped off the drywall as I wanted to see what was going on. But I think them leaving the builders insulation in place Rather than taking it off an installing a moisture barrier instead was a mistake. And then of course not sealing the vapor barrier leaving so many "holes" so to speak.

I am going to be ripping out the carpet and plan to put a moisture barrier over the entire slab. Which I will tape to the protruding vapor barrier At the bottom of the drywall all around the room to seal out whatever exterior moisture I can.

I wish I had the time and resources to rip out the whole lot of drywall, insulation etc and redo it all properly. Sadly I must live with it.

User avatar
Shannon
Posts: 11707
Joined: Fri Nov 25, 2011 11:58 pm
Location: Canada
Contact:

Re: Looking for answers to basement insulation fail

Post by Shannon » Wed Jan 02, 2019 8:00 pm

Seal the plate with canned foam or use your acoustical when you seal poly.

I’m not a fan of poly on the floor. You are better of with a moisture barrier type subfloor like Dricore IMO. Poly will keep it from breathing at all once a floor covering is installed and that will cause issues for sure
If you've found our videos or website information helpful, please considering pledging us on Patreon

Post Reply