Why Is My Floor Sagging?

A sagging floor is one of the many signs of foundation problems. There are multiple foundation issues that cause sagging floors, so carefully inspect your foundation to clear any doubts and start planning for repairs. The first problem could be wood rot on the floor joists. When a foundation is wet, the humidity opens the door for all sorts of fungal growth, including rotting wooden joists. The fungus eats the wood to survive and as a result, the wood either softens up or breaks apart.

On a related note, in crawl spaces that are frequently flooded with water, it is often the case that the wooden posts are waterlogged. Wood is an absorbent material capable of taking in a lot of water at a time. As the water gets absorbed, the wood’s cells change to accommodate the moisture, expands, and becomes softer. Even if your crawl space is no longer flooded with water, once wood has softened up, it can never go back to its previous firmness and strength. This, of course, affects the way the wood supports your floorboards.

Another reason why your floor is sagging has to do with foundation settling. When a foundation settles, the house begins to shift to one side, and this can have a major effect on the way the floor joists or posts hold up the floorboards. You would need to look for other signs of foundation settling in your foundation and around your home as well to determine if this is what is causing your floor to sag. If it is, the problem can be fixed with the use of helical or push piers. For dirt crawl spaces, sometimes what’s needed is a crawl space support jack to aid the joists.