NASCLA Accredited Commercial General ContractorThermal and Moisture ProtectionEasy
A general contractor is overseeing the installation of a new roof assembly that includes a continuous air barrier. The primary purpose of this air barrier is to:
- AEnhance the sound attenuation properties of the roof.
- BProvide structural diaphragm action for wind uplift resistance.
- CPrevent the growth of mold and mildew within the roof system.
- DReduce uncontrolled air leakage and associated energy loss.
Show answer & explanationAnswer & explanation
Correct answer: D. Reduce uncontrolled air leakage and associated energy loss.
The fundamental role of an air barrier is to minimize the uncontrolled movement of air (and the moisture it carries) into and out of the building envelope, thereby reducing energy consumption and preventing condensation.
Why the other options are wrong
- A. Some air barrier materials may offer minor sound attenuation, but it is not their primary design function.
- B. Structural diaphragm action is provided by the roof deck and its securement, not the air barrier.
- C. While air barriers can indirectly reduce mold by preventing condensation, their primary purpose is not mold prevention itself.
Air Barrier Function
An air barrier is a system of materials designed and constructed to control air flow between a conditioned space and an unconditioned space, or the outdoors.
- Reduces energy consumption by preventing air leakage.
- Controls moisture movement by stopping air-transported vapor.
- Improves thermal performance of insulation by preventing air washing.
Memory trick: Air Barriers: Stop Leaks, Save Energy, Stay Dry.