MRS Building Materials & Mold Growth 3

Question 1

Which factor most significantly accelerates mold growth on wood structural members in a crawl space?

Accepted Answer

Relative humidity consistently above 70%

Answer

Sustained relative humidity above 70% allows moisture to condense on and be absorbed by wood members, providing the water activity necessary for rapid mold growth.

Question 2

What makes paper-faced exterior sheathing (such as DensGlass) more mold-resistant than standard drywall?

Accepted Answer

It uses fiberglass mat facing instead of paper

Answer

Fiberglass mat-faced sheathings replace the organic paper facing with inorganic fiberglass, eliminating the primary cellulose food source that mold exploits on standard drywall.

Question 3

A remediator encounters mold on the underside of a roof deck in a well-ventilated attic. What is the MOST probable moisture source?

Accepted Answer

Air sealing failures allowing humid interior air to enter the attic

Answer

In ventilated attics, the most common cause of roof deck mold is warm, moist interior air bypassing insulation and air sealing and condensing on the cooler roof sheathing.

Question 4

Which substrate provides the MOST nutrients for mold and therefore supports the most vigorous growth?

Accepted Answer

Untreated softwood lumber

Answer

Untreated softwood lumber is rich in cellulose and other organic compounds that provide abundant nutrients, supporting aggressive mold colonization when moisture is present.

Question 5

What is the PRIMARY reason carpet is classified as a Category 3 (black water) removal material when flooded with sewage-contaminated water?

Accepted Answer

Carpet fibers cannot be disinfected and the backing traps contamination

Answer

Carpet and its porous backing cannot be effectively disinfected after sewage exposure, and trapped organic matter and pathogens make it a mold and pathogen reservoir that must be discarded.

(MRS) Mold Remediation Specialist Practice Test

(MRS) Mold Remediation Specialist Practice Test

MRS Building Materials & Mold Growth 3