Selecting an Underlay for a New Floor

Underlayment Floor

Different kinds of floors require special and different kinds of underlayment. This is with the exception of wood floors and carpeting. For floor coverings like natural stone which need a plywood subfloor, the underlayment is necessary to provide protection from moisture. This is the same protection you get from heated floors. In fact combining this with radiant floor heating systems provide the best protection from moisture and molds. There are several materials used as underlayment.


This type of underlayment is used almost exclusively with ceramic tiles and natural floor installation. Its ability to withstand exposure to lots of moisture makes it a great selection for areas like the bathroom.


It is a great option with great moisture proof qualities. It is used with ceramic tiles and vinyl floor covering. Its thin nature makes it useful in places where height will be an issue.


This is an alternative but usually used to cover individual cracks. It is used to provide protection to ceramic tiles from movements that can be caused by cracked concrete floors. It is available in liquid form and can be used to cover an entire floor and an underlayment.


Plywood is used as the subfloor but can easily be used as an underlayment. This is especially true when the subfloor plywood used is of poor quality and the floor covering is of material like vinyl.

Installing plywood as an underlayment for vinyl floors is a great DIY project. It provides a chance to greatly improve your home in terms of value and strength. The quality of plywood used is important for several reasons. First, manufacturers’ warranties are voided if the vinyl is placed on low standard underlayment. The recommended quality is an inch quality grade AC plywood.


  • Install a complete sheet of plywood on the longest wall of the floor. While doing this ensure the underlayment seams are not in alignment with the subfloor seams.
  • Use 1 inch deck screws to fasten the plywood. The screws should be placed at 6 inch intervals along the edges and 8 inch intervals across the plywood sheet.
  • Notch the plywood so that it meets existing floors at the doorways.
  • Place a door patching compound which has a latex additive over the seams and on the screw heads.
  • Leave the area to dry and later sand the patched areas with a sander preferably an electric one.

Where you get stuck or in the case of a complex setup, you can get help from a professional installation company. A snow melting systems installation company can best advise you on the installation of underlayment. This is because they have experience in installing such driveway heating systems whenever they are installing radiant heating systems under the floor.