BAP Building Envelope & Insulation 2

Question 1

What is the primary benefit of installing continuous insulation (ci) on the exterior of a wall assembly?

Accepted Answer

It eliminates thermal bridging through the framing members

Answer

It increases the structural load-bearing capacity of the wall

Answer

It serves as the primary vapor retarder for the assembly

Answer

It replaces the need for cavity insulation between studs

Question 2

What does the metric ACH50 represent in a blower door test?

Accepted Answer

Air changes per hour measured at a depressurization of 50 Pascals

Answer

Total conditioned air volume exchanged per hour at normal conditions

Answer

Average cubic feet per minute at 50% relative humidity

Answer

Air conditioning capacity required at an outdoor temperature of 50°F

Question 3

In a vented attic assembly, at what plane should the air barrier be installed?

Accepted Answer

At the ceiling plane — the floor of the attic above conditioned space

Answer

At the roof deck, beneath the sheathing

Answer

At the mid-depth of the attic insulation layer

Answer

At the soffit, to direct airflow into the attic

Question 4

Kraft-faced fiberglass batt insulation is classified under building codes as which class of vapor retarder?

Accepted Answer

Class II (0.1–1.0 perms)

Answer

Class I (≤0.1 perms)

Answer

Class III (1.0–10 perms)

Answer

Vapor-open (>10 perms)

Question 5

How does the stack effect influence air leakage through a building envelope?

Accepted Answer

Warm air rises creating positive pressure at the top and negative pressure at the bottom, driving infiltration and exfiltration

Answer

Cool air sinks creating positive pressure at the base, pushing air upward through the envelope uniformly

Answer

The stack effect only influences air movement in duct systems, not through the envelope

Answer

It creates equal pressure across all elevations, producing uniform air leakage

Question 6

What is the most effective method for insulating and air sealing rim joists in existing homes?

Accepted Answer

Apply closed-cell spray polyurethane foam to simultaneously insulate and air seal

Answer

Leave uninsulated to allow drying to the exterior

Answer

Install cut-and-cobbled rigid foam boards without additional air sealing

Answer

Stuff fiberglass batts into the rim joist cavity without sealing the edges

Question 7

What is the primary function of a drainage plane (water-resistive barrier) in a wall assembly?

Accepted Answer

To redirect any water that does penetrate the cladding back to the exterior

Answer

To prevent all exterior moisture from ever penetrating behind the cladding

Answer

To serve as the primary vapor retarder for the wall assembly

Answer

To provide supplemental insulating value to the exterior wall