WLFI Installation Standards & Techniques 3

Question 1

When installing engineered hardwood over a concrete slab, which installation method is NOT typically recommended by manufacturers?

Accepted Answer

Nail-down

Answer

Traditional nail-down installation is not used over concrete because nails cannot penetrate concrete properly; glue-down, floating, or staple-down (over sleepers) are the accepted methods.

Question 2

According to ASTM F710, what is the minimum on-center spacing requirement for floor flatness measurements when evaluating a concrete subfloor for hardwood installation?

Accepted Answer

6-foot radius

Answer

ASTM F710 requires flatness to be measured within a 6-foot radius, with no more than 3/16" variation, to ensure the subfloor is suitable for hardwood installation.

Question 3

During a hardwood installation inspection, an inspector finds that staggered end joints between adjacent rows are only 2 inches apart. This violates the typical minimum stagger requirement of:

Accepted Answer

6 inches

Answer

Most manufacturers and NWFA standards require end joints in adjacent rows to be staggered a minimum of 6 inches to prevent H-joint patterns and ensure structural integrity.

Question 4

What is the purpose of back-rolling adhesive when performing a glue-down hardwood installation?

Accepted Answer

To ensure uniform adhesive transfer to the back of each plank

Answer

Back-rolling or troweling adhesive onto the back of planks in addition to the subfloor ensures full transfer and eliminates hollow spots beneath the finished floor.

Question 5

Which condition requires the installer to acclimate solid hardwood flooring for a longer period before installation?

Accepted Answer

Flooring with a higher initial moisture content than the job site EMC

Answer

When flooring arrives wetter than the job site equilibrium moisture content, extended acclimation is needed to allow the wood to dry down to match the environment.

(WLFI) Wood and Laminate Flooring Inspector Practice Test

(WLFI) Wood and Laminate Flooring Inspector Practice Test

WLFI Installation Standards & Techniques 3