Installing Wood Floor - Leveling SubFloor

[dcd22]

I have about a 1/4 to 1/2 sag in my floor. I was thinking of building it up with 1/8 ply and then installing the wood floor over it. I would gradually stagged the 1/8 as to not have any major "bump" under the wood.

Do you think this will work?

 

[mattysupra]

yes thats the way to do it. All tho you will have to lay a wooden flooring compound over the top to get rid of edges and to create a gentle slope between boards. Or you could lay a thick ply 3/4inch or so over the whole lot, but will raise floor height. Or you could jack and brace the joists level and install flooring direct to joists or to new plywood installed over the joists depending on which method you go along with.

 

[dcd22]

I am thinking that the "right" way to do it is to cut out the sub floor in the area that has the issue, sister in new floor joist's (I think they are installed incorrect and the crown is down) and then re-lay the sub floor vs. trying to "patch" it.