Building Skills: Install a Subfloor
If subflooring panels can move against the joists or abutting sheets, they will squeak.
The subfloor is the layer of structural sheathing applied directly to the joists that provides a base for all the finish floors to come. Some types of flooring, such as carpet or traditional hardwood, can be installed directly on top of the subfloor. Others — such as tile, vinyl, and some engineered wood products — require an additional layer called underlayment before they are installed. The most important function of a subfloor is to create a structural diaphragm that helps to distribute wind and seismic loads through the house frame. That’s the main reason subflooring has a code-specified nailing schedule (every 6 in. on edges parallel to joists, and 12-in. spacing in the field). But perhaps the most obvious reason that proper subfloor installation is important is to minimize floor squeaks down the road.