Solid Wood Moisture Differential and Sampling Check

Compare average solid wood flooring and wood subfloor moisture readings to NWFA sampling guidance and the general board-width differential limit.

Inputs

Note

Project inputs

Project floor area (ft2)

Range: 1–100,000 ft2

Rooms receiving wood flooring

Range: 1–1,000

NWFA general guidance calls for at least 3 wood-subfloor moisture locations per room.

Average solid flooring moisture content (%)

Range: 0–40 %

Use representative, species-corrected board readings. NWFA says common handheld meter use is about 5-30% MC; verify readings outside that range with an appropriate method.

Flooring boards measured

Range: 0–100,000

Average wood subfloor moisture content (%)

Range: 0–40 %

Use representative readings with meter settings/corrections appropriate to the subfloor material. NWFA says common handheld meter use is about 5-30% MC; verify readings outside that range with an appropriate method.

Wood subfloor locations measured

Range: 0–100,000

Solid flooring face width (in)

Range: 0.5–12 in

NWFA general differential guidance distinguishes solid strip under 3 in from solid plank 3 in and wider. Not applicable to engineered flooring or concrete subfloors.