I am going to install 3/4 brazillian cherry over 3/4 t&g osb. The subfloor is nailed, screwed and glued very solid. I have 1 floor joist in the middle of the floor that is amost 1/4 in high the whole width of the room. My question is can I sand down the OSB along that particular joist say maybe 1/8 of an inch and then feather the rest with felt paper. Will this sanding of the OSB like this hurt the integritity of the sub floor.

Thanks in advance for any information

Ed

Sanding it will weaken it somewhat but it can be done. When installing your flooring, you might want to try to rack your boards out so that not many board ends land in that area. In other words, try to span over the sanded area with your joints.

3/4" (23/32")OSB is rated for floor joist spans up to 24" on center and 5/8" (19/32") is rated for 20" on center. Sanding along a raised joist will weaken it slightly but most likely you have 16" o.c. or 19.2" o.c. floor joist and a well glued and screwed 3/4" floor is really more than what you need anyway. Once you overlay with 3/4" solid flooring, you will have a mighty solid floor.

I'd first be sure I understood why the floor joist is 1/4" too high. If this is because of some moisture change or other
"temporary" condition, then sanding now and overlaying with a solid floor will be a real problem if the joist goes back down to level with the remainder of the joists.

jgb

after further investigation found that the 2 floor joists in question had a huge crown in them. they started about 8 inches from the wall and bent up. removed the OSB and staightened out the joists in question, installed new OSB and floor is flat again.

Thanks for the input

Ed