CFI Moisture Mitigation Systems 2 — Questions and Answers
Question 1: What is the primary purpose of a surface-applied moisture mitigation system on a concrete slab?
- To add structural strength to the slab
- To reduce moisture vapor emission to acceptable levels for flooring installation (Correct answer)
- To level uneven concrete surfaces
- To prevent radon gas from entering the building
Correct answer: To reduce moisture vapor emission to acceptable levels for flooring installation
Surface-applied moisture mitigation systems are designed to reduce moisture vapor emission rates (MVER) to levels acceptable for flooring adhesive and product warranties.
Question 2: Which test method measures moisture vapor emission rate (MVER) in pounds per 1,000 sq ft per 24 hours?
- ASTM F2170 (RH probe)
- ASTM F1869 (calcium chloride) (Correct answer)
- ASTM D4263 (plastic sheet)
- ASTM F710 (slab inspection)
Correct answer: ASTM F1869 (calcium chloride)
ASTM F1869 uses the calcium chloride test method to measure moisture vapor emission rate expressed in pounds per 1,000 sq ft per 24 hours.
Question 3: What relative humidity (RH) reading at 40% slab depth is generally the maximum threshold for installing most resilient flooring?
- 70% RH
- 75% RH
- 80% RH (Correct answer)
- 85% RH
Correct answer: 80% RH
Most resilient flooring manufacturers specify a maximum of 80% RH at 40% slab depth per ASTM F2170 before installation can proceed.
Question 4: A two-component epoxy moisture mitigation coating is typically applied in how many coats?
- One coat only
- Two coats, with the second applied perpendicular to the first (Correct answer)
- Three coats minimum
- As many coats as needed until the surface is glossy
Correct answer: Two coats, with the second applied perpendicular to the first
Two-component epoxy moisture mitigation systems are typically applied in two coats, with the second coat applied perpendicular to the first for uniform coverage.
Question 5: What surface preparation is most critical before applying a moisture mitigation membrane to concrete?
- Applying a concrete primer
- Shot blasting or grinding to achieve an open, porous profile (CSP 2-3) (Correct answer)
- Wetting the slab to improve adhesion
- Applying a skim coat of self-leveling underlayment
Correct answer: Shot blasting or grinding to achieve an open, porous profile (CSP 2-3)
Concrete must be mechanically prepared to a CSP 2-3 profile to allow the mitigation coating to properly bond and penetrate the surface.
Question 6: Which condition would DISQUALIFY a concrete slab from receiving a surface-applied moisture mitigation system?
- Slab age of less than 28 days
- Hydrostatic pressure (water under pressure beneath the slab) (Correct answer)
- Relative humidity of 78%
- MVER of 8 lbs per 1,000 sq ft/24 hrs
Correct answer: Hydrostatic pressure (water under pressure beneath the slab)
Hydrostatic pressure (water being forced upward under pressure) cannot be controlled by surface-applied membranes, which are designed for vapor transmission, not standing water pressure.
Question 7: What does 'pot life' refer to when working with two-component moisture mitigation systems?
- The time the mixed product remains usable before it hardens (Correct answer)
- The shelf life of the unmixed product before opening
- The time required for the coating to fully cure before flooring installation
- The maximum coverage area per mixed batch
Correct answer: The time the mixed product remains usable before it hardens
Pot life is the working time after two components are mixed before the product begins to set and can no longer be applied effectively.
CFI Moisture Mitigation Systems 2
What is the primary purpose of a surface-applied moisture mitigation system on a concrete slab?