Massachusetts Unrestricted Construction Supervisor License Practice Test

Is a vapor retarder required in a concrete floor in a heated accessory garage of a single-family dwelling?

1. No

2. Yes

3. Only if below grade

4. Only in colder climates

The correct answer is: Yes

A vapor retarder is indeed required in a concrete floor in a heated accessory garage of a single-family dwelling to prevent moisture from the ground from penetrating into the conditioned space. This is particularly important in areas where the floor is in contact with the ground, as the moisture can migrate up through the slab, causing potential issues such as mold growth, damage to materials, and decreased indoor air quality. In heated spaces, controlling moisture is crucial to maintaining comfortable living conditions and preventing structural damage. By incorporating a vapor retarder, you create a barrier that inhibits the movement of water vapor, thus protecting the integrity of the building and the health of its occupants. While certain conditions might affect the necessity for a vapor retarder, such as the climate or the specific location of the garage (e.g., if it were below grade), the general requirement remains to include a vapor retarder in heated accessory garages to ensure long-term performance and safety of the structure.