Although a home’s floor is usually thought to be simply the surface layer of a visible floor covering, a floor is a system of layered components, each of which is essential to the function and durability of the floor. And one of the more crucial layers is one that is rarely seen—the underlayment that is found just under the surface floor covering.
Anatomy of a Floor
Most floors in residential homes consist of four layers. From the top-down, they are:
1. Floor covering: This is the finished, visible flooring surface, such as hardwood planks, carpeting, ceramic tile, or vinyl. This is the layer that you see and walk on.
2. Underlayment: Just under the visible floor covering is a layer of plastic sheet and PE mat.
3. Plastic sheet: Above Subfloor is plastic sheet act as a moisture barrier preventing moisture from ground seeping into flooring material. On top plastic sheet is PE Mat, purpose is to provide a smooth, flat surface for the floor covering.
4. Subfloor: This layer is your existing floor and it can be cement, tiles, parquet, vinyl and etc.
Purpose of the Underlayment
Flooring underlayment is a thin material that rests between the floor covering above and the subfloor below. Because underlayment is a catchall term, it can take different forms depending on the flooring material is supports. Unlike the subfloor, which is part of a home’s framework and structure, the underlayment serves mostly to provide a flat smooth surface to allow for easy, attractive installation of the surface flooring. It may also serve additional functions, such as to deaden the sound of footsteps, to soften the feeling of the flooring underfoot, and in some cases to act as a moisture barrier and smoothens surface.