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Community and Q&A

Drywall install: Leave/create a gap at the bottom?

Jamie_K | Posted in General Questions on

We are looking to get started on installing drywall.  Assuming drywall should not touch concrete.

1) What should the moisture content be at or below of the framing before putting in insulation and drywall?

2a) If we want to leave 1/8″ gap or so at bottom of drywall so it is not touching top of 2 ft concrete stem wall (that is raised above the slab on grade finished floor), what would be best way to do that…put shims at bottom all the way around for them to sit bottom of drywall on or just have them cut bottom after installed?

2b) For the remaining 1/8″ gap in front of pressure treated wood on sill, how would you recommend sealing that…with caulk or spray foam?

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  1. Expert Member

    Framing is dimensioned to leave a little wiggle-room for drywall installation. Typically walls are framed with pre-cut studs that with three plates give you an 8'-1" or 9'-1" wall. With 1/2" or 5/8" board on the ceiling, and two standard sheets hung horizontally, you end up with a 3/8" gap at the bottom without cutting any boards. The wiggle room is so you can set the board into place and shove it tight to the one above. You would have to be a better boarder than any I know to get the bottom sheet to touch the slab with no gap, so don't worry, one will appear anyway.

    I'll leave others more knowledgeable to answer what you should use to seal the gap. It probably depends on what air-sealing strategy you are using.

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