Our basement floor developed a bump. I only just discovered it, in a crawspace under the stairs, so there is no knowing how many years it has been there. The left end of the ruler is not touching the floor, because the bump continues off to the right, although to a much lesser extent.
How do I find out if this is a problem? I do not know what kind of professional to call.
Janet
Replies
The concrete in that area is all of an inch thick. (It is not at all unusual for basement concrete to be only maybe two inches thick, and a "rat slab" in a crawl is apt to be thinner still.) What is likely happening is that "expansive" soil is pushing up, perhaps combined with the house foundation sinking slightly. This can be exacerbated by a high water table.
So long as it's in an unoccupied area and there are no associated problems with water infiltration then it's only a cosmetic problem.
Perhaps...
Perhaps a tree root is under the slab? They manage to buckle sidewalks real well. If so, I might check for movement once a year. If it is a root and I saw movement, I might take action.
Good luck.
How old is the house (or this portion of it)? Not only does the likelihood of such a problem increase with age, but standards (and inspections) were weaker decades ago, making the likelihood greater still.
Take up the loose concrete...
Take up the loose concrete and see what's under there...probably a root...is there a tree nearby - just outside the wall? The concrete is not offering any usefull purpose bulged up like this.
Tap it lightly with a small hammer and see if it sounds hollow. or feels loose. If it does you could knock it out easily and place a patch there. If not it's probably a result of sloppy work years ago and not worth woryring about.