Chapter 6 of 810% of exam
Wood Flooring Installation
Wood Flooring is about 10% of the C-15 exam: moisture testing, layout, installation, sanding and finishing. This page is a short survey; the PrepPass C-15 study guide teaches each step from federal specifications, the USDA Wood Handbook and manufacturers' instructions.
Moisture
Test the subfloor and flooring with a meter set for the species. One manufacturer caps the subfloor at 12% and the difference at 4% (2% for boards over 3 in.).
Recommended moisture content
8% average in most of the U.S., 6% in the dry southwest, 11% in damp coastal areas.
USDA Wood Handbook, Ch. 13Sanding and finishing
At least three progressively finer cuts, one of the first two at 45° to the grain; seal within 8 hours of the final cut.
Oily rags
Store in a listed disposal container emptied daily.
2025 CFC §304.3.1