BPI Insulation Standards 3

Question 1

What is the recommended practice when insulating a cathedral ceiling to avoid moisture problems?

Accepted Answer

Maintain a ventilation channel between insulation and roof deck

Answer

A ventilation channel (typically 1–2 inches) between insulation and the roof deck allows moisture to escape and prevents ice dams and rot.

Question 2

According to BPI standards, what area must be air sealed before adding attic insulation?

Accepted Answer

All penetrations including top plates, wiring, plumbing, and HVAC bypasses

Answer

BPI requires comprehensive air sealing of all attic bypasses — including top plates, plumbing penetrations, electrical wiring, and HVAC chases — before adding insulation.

Question 3

Which of the following best describes open-cell spray foam insulation?

Accepted Answer

Low density, vapor permeable, R-3.5 per inch

Answer

Open-cell SPF has a low density (~0.5 pcf), is vapor permeable, and provides approximately R-3.5 per inch.

Question 4

A BPI analyst finds R-11 insulation in an exterior wall cavity rated for R-13. What is the most likely cause?

Accepted Answer

Compression of the insulation within the cavity

Answer

Compressing fiberglass batt insulation reduces its thickness and therefore its R-value; R-13 batt compressed into an R-11 space loses thermal performance.

Question 5

What is the primary difference between vapor retarders classified as Class I and Class II per IRC?

Accepted Answer

Class I has a perm rating ≤0.1; Class II has a perm rating 0.1–1.0

Answer

Per IRC, Class I vapor retarders have a permeance ≤0.1 perm (e.g., polyethylene), while Class II have 0.1–1.0 perm (e.g., kraft-faced batts).

(BPI) Building Performance Institute Certified Practice Test

(BPI) Building Performance Institute Certified Practice Test

BPI Insulation Standards 3