Before reinstalling wood flooring over a previously wet subfloor
Reviewed and updated September 24, 2026
A dry-looking surface is not the moisture record an installer needs before installing wood flooring. The NWFA installation guide calls for moisture assessment of the wood flooring and the subfloor, using a method suited to the material.
For wood subfloors, the guide calls for representative readings, documentation and correction of an identified moisture problem before wood-floor installation. It does not turn one unexplained meter reading into permission to proceed.
NWFA explains that wood-subfloor composition can affect readings and directs users to the meter manufacturer's settings, methods and correction guidance.
Notice next: Ask which material was measured, which meter and settings were used, and where the reading was taken.
NWFA calls for readings representative of the project and documentation of the results.
Notice next: Ask to see the location record rather than relying on one number or a verbal statement that the surface feels dry.
The guide says elevated readings and the moisture origin must be addressed before wood-floor installation proceeds.
Notice next: Ask the installer to explain the unresolved condition and the evidence needed to decide whether installation can proceed.
No universal moisture percentage, drying duration or structural-strength test is provided.
Concrete, resilient-flooring systems and complete restoration clearance need their own applicable evidence.