CFI Subfloor Preparation & Assessment 2 — Questions and Answers
Question 1: What is the maximum recommended moisture content for a wood subfloor before installing hardwood flooring?
- 12% (Correct answer)
- 19%
- 8%
- 15%
Correct answer: 12%
Most hardwood flooring manufacturers specify that the wood subfloor moisture content should not exceed 12% prior to installation.
Question 2: What type of fastener is most appropriate for securing a squeaky subfloor panel before installing hardwood?
- Ring-shank screw (Correct answer)
- Smooth-shank nail
- Staple
- Adhesive only
Correct answer: Ring-shank screw
Ring-shank screws provide superior holding power and are less likely to back out over time, effectively eliminating subfloor squeaks.
Question 3: When a wood subfloor has a low spot greater than 3/16 inch, what is the standard correction method?
- Apply a floor-leveling compound to fill the area (Correct answer)
- Tear out and replace the entire panel
- Shim from below only
- Sand the surrounding high areas down
Correct answer: Apply a floor-leveling compound to fill the area
Floor-leveling compound is feathered into the low spot to bring it flush with the surrounding surface within tolerance.
Question 4: What spacing should be maintained between plywood subfloor panels during installation to allow for expansion?
- 1/8 inch (Correct answer)
- 1/4 inch
- 1/16 inch
- No gap needed
Correct answer: 1/8 inch
A 1/8-inch gap between plywood panels accommodates seasonal wood expansion and prevents subfloor buckling.
Question 5: Which subfloor material is NOT acceptable as a direct substrate for most glue-down resilient flooring?
- Particleboard (Correct answer)
- Plywood
- Concrete
- Cement board
Correct answer: Particleboard
Particleboard absorbs moisture and swells when wet, causing adhesive failure and floor delamination; it is not an acceptable substrate for glue-down resilient flooring.
Question 6: What is the purpose of performing a 'bond test' (tape test) before installing adhesive-backed flooring?
- To confirm the adhesive will adhere to the substrate (Correct answer)
- To measure subfloor moisture
- To check for level
- To test grout compatibility
Correct answer: To confirm the adhesive will adhere to the substrate
A tape or bond test applies a small section of adhesive to the substrate to verify that the substrate surface will accept and hold the adhesive.
What is the maximum recommended moisture content for a wood subfloor before installing hardwood flooring?