Definitions for "Underlayment"
The sheathing material usually found beneath the floor sheathing of a modular system. May also refer to the sheathing found beneath the exterior finish metal or wood on the exterior of a modular.
(1) A one-quarter-inch material placed over the subfloor plywood sheathing and under finish coverings, such as vinyl flooring, to provide a smooth, even surface. (2) A secondary roofing layer that is waterproof or water-resistant, installed on the roof deck and beneath shingles or other roof-finishing layer.
Layer of material usually installed on or over a subfloor that provides a surface suitable to receive a new floor covering.
Keywords:  slabs, mortar, concrete, plane, thin
An application of a relatively thin layer of mortar primarily used to level out-of-plane surfaces such as concrete slabs.
Keywords:  pad, carpet, placed
a pad placed under a carpet