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Maxiko
Gaps between old wood floor and exterior wall
Maxiko

I've had to remove the plaster walls along the exterior walls of my 150-year-old stone house to install insulation. (I know how strongly some of you feel about removing plaster. Just believe me; it was necessary.)

In quite a few places, the old floor does not meet the inner surface of the stone wall, leaving too much of a gap to install the sill plates for the new stud walls snug against the exterior wall. In some places, we can move the sill plate onto the floor, but this will increase the cost of spray insulation since the quantity of insulation needed will increase. In other places, interior doors are too close to the wall to be able to do this without blocking the door (unless we use 2X2 studs).

Is there a way to fill and level the gaps (some kind of mortar?) in order to install the sill plates right along the wall, where I'd prefer to put them? (There will still be gaps between the new studs and the exterior wall, since the walls are anything but straight. This is an advantage, actually, for spray insulating.)

keith3267
Re: Gaps between old wood floor and exterior wall
keith3267

The wood floors expand and contract with changes in temperature and humidity so no, you can't fill the gaps with mortar. You should not put your sill plates tight against the stone wall either. BTW, Just how much is this gap?

Maxiko
Re: Gaps between old wood floor and exterior wall
Maxiko

Thanks for the reply. I should've said that I'm not putting the plates right up against the wall. There's some vertical strapping (1.25" X 2.25") nailed into the stone/brick that was used as a nailer for the lath, and I'm leaving those in to leave the bricks and parging undisturbed. The plates line up with the outside edge of the strapping. Even so, there are some gaps of about 2-3 inches even from the edge of the strapping, leaving very little to nail the 2X4 onto. (I keep trying to upload a picture but it won't work for some reason.)

Mastercarpentry
Re: Gaps between old wood floor and exterior wall
Mastercarpentry

Pics should be linked to from a hosting site like photobucket or similar. Don't forget that the finished room will have plaster or sheetrock, baseboard, and shoe molding covering that gap. Old (and some newer) houses often have flooring stopped well short of the studs since these will cover the shortage, but 2" is the most you usually get and that's pushing things, 1 1/2" or less is more in line with modern molding thicknesses.

Phil

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