CFI Moisture Mitigation Systems 5 — Questions and Answers
Question 1: Which scenario would cause a calcium chloride (ASTM F1869) test to give a falsely LOW moisture reading?
- HVAC running continuously during the test
- Testing on a very cold slab with low ambient temperature (Correct answer)
- Leaving the kit sealed for 72 hours exactly
- High ambient relative humidity in the room
Correct answer: Testing on a very cold slab with low ambient temperature
Cold slab temperatures slow vapor emission, resulting in lower calcium chloride weight gain and an artificially low MVER reading that does not reflect real service conditions.
Question 2: What does 'alkalinity' of a concrete slab have to do with moisture mitigation?
- High alkalinity is beneficial and improves adhesive bond strength
- High alkalinity caused by moisture can destroy adhesive bonds and cause pH-sensitive flooring to fail (Correct answer)
- Alkalinity only affects ceramic tile installation
- Alkalinity readings above 7.0 require a primer before moisture testing
Correct answer: High alkalinity caused by moisture can destroy adhesive bonds and cause pH-sensitive flooring to fail
Moisture moving through concrete carries alkaline salts to the surface; this high pH environment can break down adhesives and degrade pH-sensitive flooring products.
Question 3: Which flooring installation method is considered the most moisture-tolerant for use over problematic concrete slabs?
- Full-spread adhesive glue-down
- Floating installation with a foam underlayment (Correct answer)
- Nail-down solid hardwood
- Double-stick adhesive installation
Correct answer: Floating installation with a foam underlayment
Floating floor installations do not bond directly to the slab, allowing some moisture tolerance, though a vapor retarder is still typically required beneath them.
Question 4: When a moisture mitigation membrane is required to span cracks in a concrete slab, what additional step is typically needed?
- Apply extra coats of mitigation coating over the entire slab
- Fill or reinforce cracks with a flexible crack-isolation material before applying the membrane (Correct answer)
- Grind the cracks flush and apply only one coat
- Cover the crack with duct tape before coating
Correct answer: Fill or reinforce cracks with a flexible crack-isolation material before applying the membrane
Active or moving cracks must be filled with a flexible polyurethane or epoxy filler and may require crack-isolation fabric bridging before the membrane to prevent future cracking through the coating.
Question 5: What does the abbreviation 'CSP' stand for in the context of concrete surface preparation for coatings?
- Concrete Surface Profile (Correct answer)
- Coated Slab Porosity
- Crystalline Sealer Penetration
- Calcium Silicate Primer
Correct answer: Concrete Surface Profile
CSP stands for Concrete Surface Profile, a scale from 1–9 defined by ICRI that describes the texture and roughness of prepared concrete surfaces.
Question 6: A moisture mitigation system warranty is typically voided if which condition exists at the time of installation?
- Concrete age is greater than 5 years
- Slab RH exceeds the product's rated maximum at the time of application (Correct answer)
- The flooring installed over it is a luxury vinyl plank
- The slab contains fly ash in its mix design
Correct answer: Slab RH exceeds the product's rated maximum at the time of application
Applying a moisture mitigation product when slab RH or MVER exceeds the product's specified maximum rated threshold voids the product warranty as the coating is not designed for that extreme.
Question 7: What is the purpose of conducting a 'bond test' (pull test) after applying a moisture mitigation membrane?
- To measure the thickness of the applied coating
- To verify that the mitigation membrane has adequately bonded to the concrete substrate (Correct answer)
- To check for pinholes in the membrane surface
- To confirm the moisture vapor emission rate has been reduced
Correct answer: To verify that the mitigation membrane has adequately bonded to the concrete substrate
A pull test measures the tensile bond strength of the cured membrane to the substrate, confirming the surface preparation was adequate and the coating has properly adhered.
CFI Moisture Mitigation Systems 5
Which scenario would cause a calcium chloride (ASTM F1869) test to give a falsely LOW moisture reading?