CFI Subfloor Assessment & Preparation 5

Question 1

When assessing an existing subfloor for a new flooring installation, what is the FIRST step a CFI installer should perform?

Accepted Answer

Conduct a visual and physical inspection for structural integrity, moisture, and flatness

Answer

A thorough inspection must precede any preparation work to identify all deficiencies and develop the correct remediation plan.

Question 2

What is the minimum compressive strength required for a self-leveling underlayment used beneath ceramic tile?

Accepted Answer

3,000 psi

Answer

Self-leveling underlayments used under tile must achieve a minimum of 3,000 psi compressive strength to withstand point loads without cracking.

Question 3

A subfloor is found to have localized soft spots where the wood is spongy underfoot. What does this indicate?

Accepted Answer

Moisture damage or rot has compromised the panel's structural integrity

Answer

Spongy areas indicate delamination or rot from moisture intrusion, requiring panel replacement rather than surface patching.

Question 4

What product is used to fill wide cracks (over 1/4 inch) in a concrete slab before flooring installation?

Accepted Answer

Hydraulic cement or epoxy filler

Answer

Wide cracks require a rigid hydraulic cement or epoxy crack filler to prevent movement from telegraphing through the finished floor.

Question 5

What is the ASTM standard that governs the use of the anhydrous calcium chloride test for measuring moisture vapor emission from concrete?

Accepted Answer

ASTM F1869

Answer

ASTM F1869 is the standard test method for measuring moisture vapor emission rate (MVER) of concrete floors using anhydrous calcium chloride.

(CFI) Certified Flooring Installer Practice Test