How to Soundproof a Wooden Floor

Before any material is installed, measure the entire floor area and plan for full wall-to-wall coverage. Soundproofing underlayment only works when it’s continuous. Gaps, exposed subfloor, or partial coverage allow impact vibration to bypass the isolation layer entirely.

Take note of door thresholds, fixed cabinetry, and floor penetrations so the underlayment can be cleanly trimmed without breaks.

Roll UnderBlock rubber underlayment directly over the subfloor, maintaining 100% coverage across the entire surface. Seams should be tightly butted—not overlapped—and run wall to wall.

Adhering the underlayment is optional. In many builds, the weight of the finished floor assembly is enough to hold it in place. If you want to use an adhesive, Mapei rubber adhesive is an excellent choice. Just double check with the finished flooring manufacturer that it is compatible.

The goal is simple: create an unbroken isolation layer that absorbs footfall energy before it enters the structure below.

Install a plywood layer on top of the rubber underlayment to create a stable base for the finished floor. Never nail or screw through the underlayment into the subfloor. Doing so creates rigid mechanical connections that allow vibration to pass straight through, defeating the purpose of the rubber layer.

How this step is handled depends on the type of wood floor being installed:

Nail-Down Hardwood Floors

A plywood layer is required. The finished hardwood is nailed into the plywood only, not through the rubber layer and subfloor.

Glue-In LVT or Thin Engineered Wood Floors

A plywood layer is required to provide stiffness and a proper bonding surface.

Floating Wood or Laminate Floors

A plywood layer is typically not needed, as these floors are designed to float above the underlayment without fasteners.

Install the final flooring material according to the flooring manufacturer’s specifications. Expansion gaps, transition details, and perimeter spacing should be followed exactly.

Once installed, seal perimeter gaps with acoustical sealant before baseboards are installed. This prevents sound from flanking around the treated floor assembly.