Armstrong Flooring resilient floors are recommended on suspended wood subfloors with a 1/4″ underlayment (see product installation systems for exceptions) and a minimum of 18″ of well-ventilated air space below. Armstrong Flooring does not recommend installing resilient flooring on wood subfloors applied directly over concrete or on sleeper construction
subfloors over on or below grade concrete.
Loading requirements for subfloors are normally set by various building codes on both local and national levels. Trade associations (such as APA – The Engineered Wood Association) provide structural guidelines for meeting various code requirements. Subfloor panels are commonly marked with span ratings showing the maximum center-to-center spacing in inches of supports over which the panels should be placed.
APA-Rated STURD-I-FLOOR
Panels can be manufactured as conventional plywood, as a composite or as oriented strand board.
Armstrong Flooring recommends an additional 1/4″ or thicker layer of APA plywood underlayment.
When installing directly over wood subfloors, the moisture content of the subfloor should be 13% or less.
Single-layer wood subfloors increase the potential for staining from the panel components, coated nails, construction adhesives, spills, overspray and show-through from texture and mechanical or water damage when resilient floors are installed directly to single-layer STURD-I-FLOOR.