CFI Moisture Testing & Environmental Conditions 1 — Questions and Answers
Question 1: Which ASTM standard test method is used to measure moisture vapor emission rate (MVER) from a concrete slab?
- ASTM F1869 (Correct answer)
- ASTM F2170
- ASTM D4263
- ASTM E741
Correct answer: ASTM F1869
ASTM F1869 is the calcium chloride test method for measuring moisture vapor emission rate from concrete slabs prior to flooring installation.
Question 2: What unit of measurement does the ASTM F1869 calcium chloride test express moisture vapor emission in?
- Pounds per 1,000 sq ft per 24 hours (Correct answer)
- Grams per meter squared per day
- Relative humidity percentage
- Grains per hour
Correct answer: Pounds per 1,000 sq ft per 24 hours
The calcium chloride test result is expressed in pounds of moisture vapor emitted per 1,000 square feet per 24 hours.
Question 3: What maximum MVER do most flooring adhesive manufacturers specify for concrete slab installations?
- 3 lbs per 1,000 sq ft/24 hrs (Correct answer)
- 10 lbs per 1,000 sq ft/24 hrs
- 6 lbs per 1,000 sq ft/24 hrs
- 1 lb per 1,000 sq ft/24 hrs
Correct answer: 3 lbs per 1,000 sq ft/24 hrs
Most standard flooring adhesives are rated for substrates emitting no more than 3 lbs/1,000 sq ft/24 hrs; higher emissions require moisture-tolerant adhesives or a barrier system.
Question 4: What does the ASTM F2170 test method measure in a concrete slab?
- Relative humidity (RH) within the slab using an in-situ probe (Correct answer)
- Surface moisture emission rate
- Slab pH level
- Concrete compressive strength
Correct answer: Relative humidity (RH) within the slab using an in-situ probe
ASTM F2170 measures internal relative humidity within the concrete slab by placing probes at a specified depth, reflecting the slab's true moisture condition.
Question 5: At what depth within the concrete slab are F2170 RH probes typically installed?
- 40% of slab depth for slabs drying from one side (Correct answer)
- At the surface only
- At the very center always
- 2 inches from the top regardless of thickness
Correct answer: 40% of slab depth for slabs drying from one side
For slabs drying from one side, ASTM F2170 specifies probe installation at 40% of the slab's total thickness to capture representative moisture levels.
Question 6: What maximum relative humidity reading does ASTM F2170 allow for most standard adhesive-set flooring installations?
- 75% RH (Correct answer)
- 90% RH
- 60% RH
- 85% RH
Correct answer: 75% RH
Most flooring manufacturers and the ASTM F2170 protocol specify a maximum of 75% RH in the slab for standard adhesive installations; exceeding this requires special systems.
CFI Moisture Testing & Environmental Conditions 1
Which ASTM standard test method is used to measure moisture vapor emission rate (MVER) from a concrete slab?