Floor Joist Crown

If the crown is less than about 3 8 you can just sand it down with a belt sander.

Floor joist crown.

You need to make sure the hump in each floor joist is pointing to the sky. It appears the previous tiler tried to deal with the crown by putting a grout line directly on joist and tilting the tile slightly but it is still quite noticeable. The joists that is cut will stay crowned unless acted upon by an outside force though it may drop a teensy bit. If it s really bad you might have to pull the sub floor and plain down the joist but that s not much fun.

I have full access under the joist a 2x12 with a full basement. The joist on the other side of the crowned joist was properly level meaning it was in plane with the end joist. Then use screws to draw down the crown then set the splicing joist in tight. Not enough for concern.

Joists that have severe crowns need to be set aside or some of the crown needs to be trimmed off so the floor remains fairly flat once covered with plywood or oriented strand board. Take a look in the crawl space to see if anything is forcing the joist up beam stub wall. This is a crown. They sure don t build them like they used to.

Between it and the end joist just 12 inches away there was a 5 8 inch drop. One of the joists close to the end joist of the house had a very significant crown in it.