Is some paper-faced drywall okay in the basement?
I have stem walls with wood framing in some sections of 2×6 framing in my basement. I will finish the basement by using open-cell foam to fill the 2×6 voids. For the poured walls, I will adhere 2 inches of XPS to the walls, add 1 5/8 metal studs, and cover the whole thing with drywall.
The basement also hosts my HVAC system. The design calls for returning all the air in the house by drawing it into the basement. (We are installing a couple of louvered doors to make that work. With a 3,000 square-foot house and 2 tons of heat pump, the system should run enough to keep moisture below 50 percent. (I’m also installing two small ERVs for fresh air.)
I’ve included all this detail because I want to give a complete picture of anticipated conditions in the house and basement.
My drywall plan for the basement calls for using GlasRoc (mold rating of 10) on the portions of the wall that cover rigid foam and concrete and AirRenew drywall on the sections with spray foam and wood framing. I could use GlasRoc everywhere, but I want to take advantage of AirRenew’s formaldehyde capture feature.
Does anyone see a problem with this approach? I’m meeting with the drywall contractor tomorrow and would like to have my ducks in a row.
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Replies
Steven,
Yes, you can use paper-faced drywall in the location you mention.
I'm confused by these sentences, however: "The design calls for returning all the air in the house by drawing it into the basement. (We are installing a couple of louvered doors to make that work.)"
If you have a forced-air heating system, you should have a ducted return-air system. It sounds as if you are omitting the return air ducts, and just pulling return air from your basement. If that's your plan, it's not a recommended method.
Hi Martin:
Thanks for the input. On the air return, I'm describing it poorly. The design was done by a very competent HVAC engineer. I'm confident it will work.
Steven,
So, if the forced air system includes return-air ducts, why do you need a louvered door?
Hi Martin:
The system does not include return air ducts. All air is returned to the air handler in the basement. The basement door and equipment room doors have to be louvered to allow air flow. I've had two Energy Star Certified HVAC installers review the design, and they both agree it will work just fine.
PM me if you want to talk to the designer. It might make an interesting article for the site or Fine Home Building. I'm sure he will give you an earful on why houses have systems that are too large and complicated to create a comfortable year-round environment.
Steven,
Unless every single door in the house -- including all of your bedroom doors -- is louvered, I think you are asking for trouble. You might want to read the following article -- or perhaps suggest it to your HVAC system designer: Return-Air Problems.
I understand the door issue, but we have left most of the space open. Beside the louvered doors, we have five pocket doors, which will be almost always open.