What is the Purpose of Underlayment for Flooring?

The bottom layer of flooring is a thin layer of high-density protective foam that provides a barrier to protect hardwoods from mold, mildew, and moisture. It also helps to dampen sound and reduce floor wear. The subfloor is a thin layer of material such as fiber, felt, rubber, or foam that cushions, absorbs sound, insulates, and reduces floor wear. For laminate or engineered wood floors, it provides a “vapor barrier” to prevent moisture from entering and damaging the floor.

Subfloors are usually made of plywood, concrete, oriented fiberboard (OSB), or wood planks. When the subfloor is in poor condition or requires sound insulation, a subfloor can be useful. Certain lower layers come with a built-in vapor barrier to prevent moisture from reaching the floor. It is important to follow the manufacturer's recommendations on the type of base ideal for each type of pavement.

If installing laminate floors with a pre-bonded subfloor on a cement subfloor, a vapor barrier must be installed to prevent moisture from leaking through the subfloor. It is recommended to purchase the floor material before buying a lower layer. It is best to invest in quality subfloors as performance generally follows the price of subfloors. The correct selection and installation of subfloors and underlayment is essential for proper wear and stability of any pavement.

Steam subfloors protect the floor from any moisture that may seep from the cement subfloor. Different models of bases are designed for various types of floors and for different purposes. If installing laminate flooring on a wooden subfloor, a standard subfloor should be used for the premium subfloor. If the subfloor is not flat or smooth, a subfloor provides a better surface for installing the upper floor.

Some high-end types have subfloors in their buildings due to improvements in materials for laminate floors. It is important to review the floor installation instructions to follow what they recommend for the subfloor. If installing floors for a specific purpose such as sound dampening, the best layers of acoustic insulation should be purchased. Whether DIY or hiring a professional installer, carefully consider subfloor options for flooring.