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Community and Q&A

Air sealing the bottoms of walls

carlosdanger | Posted in Energy Efficiency and Durability on

We are finishing up a gut renovation of a house and sheet rock has just been hung. I was wondering whether or not I should try to air seal the space between the bottom of the sheet rock and the floor. I’ve found some differing opinions on whether or not to do this and how to go about it and I was hoping that some of you might want to weigh in. Right now the walls are insulated with unfaced roxul mineral wool. The exterior walls have old aluminum siding that will need to be replaced in a few years and no house wrap. To me, it looks like this space might leak a lot of air and be a source of dust entering the house from inside the walls. Thanks for any responses.

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  1. GBA Editor
    Martin Holladay | | #1

    Yes, you need to seal air leakage at this point. You can either seal the gap between the drywall and the subfloor with caulk, or, if the gap is particularly wide, you use caulk when installing the baseboard.

    If you use the latter method, you may want to caulk the crack between your finish flooring and the bottom plate of your wall. Make sure that you include caulk where the baseboard meets the finish flooring, as well as where the baseboard meets the drywall.

  2. carlosdanger | | #2

    Thanks. Will any normal caulking do or is there a specific type that is best? I've read some places that a caulk that does not fully harden is best because it allows the drywall to expand and contract. Thanks again.

  3. GBA Editor
    Martin Holladay | | #3

    I would choose silicone or polyurethane caulk, not latex caulk. If you plan to caulk the baseboard, choose a color that will be unobtrusive; sometimes, clear caulk is best.

  4. carlosdanger | | #4

    Great. Thanks again.

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