An "Air Gap Subfloor" is a T&G Plywood or OSB sheeting that is installed over a plastic membrane (Platon) that raises the wood off the floor. All of the seams in the plastic are sealed to prevent moisture from damaging the wood and allowing air to flow beneath it, thus creating the "Air Gap".
In the past, many builders would simply lay a sheet of plastic over the floor and then place the wood on top of it. As it turns out, this was a very bad approach to use, due to the fact that the moisture gets trapped beneath the plastic and causes mold and rotten wood.
Why do I want a Professional Subfloor?
Today, you can install your own "do it yourself" subfloor that is sold by many large
retailers or you can get a professionally installed sealed subfloor. The benefits of
a professional subfloor are:
Larger sheets of wood. We install 32 square feet at a time, versus 4 square
feet for the "do it yourself" product.
All joints are sealed to prevent moisture penetration versus no sealing for
the "do it yourself" product.
All subflooring is screwed to the concrete with rust proof TapCon screws to
make a solid surface versus a floating floor that can sound hollow.
A professional product versus a "Handyman" product.
There are many benefits to having and Air Gap Subfloor: