CMA CMA Moisture & Building Science

Question 1

What is the primary driving force that allows moisture to move through building materials by capillary action?

Accepted Answer

Surface tension in pore spaces

Answer

Vapor pressure differential

Answer

Thermal gradient

Answer

Wind-driven rain pressure

Question 2

Which relative humidity (RH) range is generally considered the threshold above which mold growth is likely to begin on building materials?

Accepted Answer

Above 60% RH

Answer

Above 50% RH

Answer

Above 70% RH

Answer

Above 80% RH

Question 3

In building science, what does the term 'dew point' refer to?

Accepted Answer

The temperature at which condensation forms on a surface

Answer

The lowest outdoor temperature recorded in a day

Answer

The moisture content of building materials

Answer

The point at which rain penetrates a wall assembly

Question 4

Which type of vapor retarder is classified as Class I under the International Residential Code (IRC)?

Accepted Answer

Polyethylene sheeting (6 mil)

Answer

Kraft-faced batts

Answer

Latex paint

Answer

House wrap

Question 5

What is the primary cause of interstitial condensation in wall assemblies?

Accepted Answer

Warm moist air meeting a cold surface within the wall cavity

Answer

Exterior rain wetting the cladding

Answer

Plumbing leaks inside the wall

Answer

Foundation moisture wicking upward

Question 6

Which building material typically has the highest moisture sorption capacity, making it a significant mold substrate risk?

Accepted Answer

Paper-faced gypsum drywall

Answer

Concrete block

Answer

Ceramic tile

Answer

Glass fiber insulation