I’m purchasing a two-story home, and I noticed what I think is a problem with the floors. When you walk in the front door, there is a staircase on the left and a hallway on the right with a half bath. It seems to me the floors are bowed in the hall, but the tile is not cracked. I placed a straight edge on the floor, and it has a slight hump. Should I walk away from a house like this?
I would not walk away if the floors are the only issue. A good home inspector or structural engineer should be able to report on what’s happening.
Here’s an explanation that I have used many times to explain why there is a hump in a hall floor: The home has floor joists set every 16 inches, and they normally run from the front of the home to the rear. As you walk down the hall from the entry toward the back of the home, you will be standing on a supporting foundation wall or support beam at the center of the home. This is where the floor joists overlap. From that point to the back of the home there is no hump.
Why? Usually there are three walls at the entry, two for the stairs and one for the 3-foot-wide hall. The hall wall is often used for a closet or half bathroom. Either the stair wall or the hall wall is pushing down on the subfloor and in between two of the floor joists. The weight causes a hump to form between the neighboring floor joists. If the hall has carpet, the hump is not as noticeable. Hardwood, sheet flooring and tile are more likely to reveal a hump.
In your instance, the tile is not cracked because the hump formed during construction. The floor was leveled by the tile setter, and then the tile was installed over the existing hump.
There is really no need to try to take the hump out of the floor other than aesthetics. If you want to beef up the support for the stair wall, you can install 2- by 10-inch blocks cut to fit between two of the joists under the stair wall. Set the blocks perpendicular to the joists and install one every 16 inches.