The plywood floor system attached to floor joists when framing a structure

A floor beneath the finish floor designed to strengthen the bearing surface and prevent dust from passing through floors.

Boards or plywood installed over joists on which the finish floor is laid.

Material installed before finish flooring materials.

are boards or plywood sheets laid on joists over which a finish floor is to be laid.

The concrete or wood floor surface lying under the finished floor. Pre-hung door assemblies are installed atop the sub-floor.

Plywood sheets that are nailed to the floor joists prior to fastening the finished floor product.

boards nailed directly to floor joists, used as base for finished floorboards or carpets.