Hi all,
I am tearing into a 110 year-old house and would like to replace all the flooring. The existing floor consists of maple T&G over pine shiplap over rough cut pine planks. All of the existing flooring runs in the same direction (perp. to joists) and the variation in the subfloor layers resulted in a very wavy finish floor with a lot of gaps. I cut out a section to get a better look, as shown in the attached pic, and found that the top two layers are butted to the wall, but the bottom plank flooring (which looks dry-rotted) goes under the walls. It seems like I should remove everything to exposed joists and start fresh with plywood subfloor, correct? I’m wondering how to handle the perimeter and load bearing interior walls, where the walls are on top of the subfloor- is it acceptable to just remove it up to the wall and leave what is under the walls in place? Should I be tying the new subfloor to the existing walls somehow?
Any thoughts appreciated,
Replies
Shawn
At the very minimum, you need to support those walls that run with the joists. If you cut out the flooring up to the wall, and that wall is not right on a joist, you be screwed.
Further, the loading on a single joist will be picked up a bit by the joists on either side. You won't experience failure, but cracks to plaster might occur.
Don't forget wiring, plumbing and heat/return air might be in those walls.
Cross blocking between joists can be done and this would support your walls when no joist is directly below.
Thanks for the reply Calvin,
This is a small house and there is only one interior partion wall to deal with, which runs down the center of the space perpendicular to the joists.
I guess I am more concerned about the fact that the bottom layer of subfloor appears to be somewhat deteriorated. Since it is underneath all the load bearing walls/perimeter walls of the house, I have this unpleasant vision of the house 'settling' as the wood continues to deteriorate over time. Even if I attempt to reinforce with blocking from underneath, I would still have the old wood sandwiched in between.
I can cut it out right up to the walls, but not under the walls, so wondering if I should be concerned about this and how to properly deal with it. I'd like to spend the rest of my life in this house (and I'm only 39!), so I don't want to do remodeling that isn't going to last...am I overreacting about this?
Shawn
You have access below. This should allow you to remove and replace the sections of flooriing under that parallel wall..............as well as temporarily supporting it while you do that.
I'll offer the observation that you need to plan this very carefully. Lots of variables depending on how the walls run, how much access is possible from below, etc. And keep in mind that if the subfloor is so rotten then likely some of the joists are as well.
I have full access to everything below. The house was raised up in the 40s to put a full basement underneath. The original joists are actual 2" X 6", but were on 32" centers. When the basement was put in (I presume), they added another joist in every bay, so the spacing is about 16"oc. The joists all look solid, but I could sister in additional support if necessary after I have removed the subfloor.
The best way to remove it though is...
a bunch of guys with strong backs and weak minds that work for beer and lunch. Failing that, a truck load of visitors that speak funny and work for cash wouldn't be bad.
You might be able to do the subfloor under the walls a small section at a time, just like repairing perimeter rot. Dig out about a 2 foot section of the subfloor from under the wall, then pound in a section of plywood wide enough to fill the cleaned out section & long enough to cover a joist bay or two, or three, then repeat.