The subfloor of a building is the rough floor that is laid down as a base for the finished floor. The finished floor would be tile, carpet, vinyl or hardwood. The subfloor is often created from plywood and is affixed directly to the flooring studs or concrete floor slab, depending on the location of the property and how it was built. The subfloor needs to be level and smooth in order to help set up for the finished floor. Often there is adhesive used on the subfloor in order to make sure that the finished floor stays in place. It is absolutely essential that the subflooring of a building is affixed to the studs or concrete below. They need to be attached to the floor joists so that they do not warp or bend in humidity and destroy the finished flooring.
When purchasing a home you may find that the flooring in the home needs to be replaced. If the contractor removes the finished flooring he or she will need to confirm the condition of the subfloor. If the finished flooring had areas that were warped or pushing up, there may be an issue with how the subflooring was attached. In some cases, if the subflooring is badly damaged, it may be necessary to completely replace the subflooring in order to lay down a new finished floor.