InterNACHI Roofing Systems and Components 2

Question 1

What is the minimum recommended slope for asphalt shingles according to standard installation practices?

Accepted Answer

2:12

Answer

Asphalt shingles require a minimum slope of 2:12 (2 inches of rise per 12 inches of run) for standard installation.

Question 2

Which roof component prevents water from entering at the intersection of a roof plane and a vertical wall?

Accepted Answer

Step flashing

Answer

Step flashing consists of L-shaped metal pieces installed in courses along with the shingles where a roof meets a vertical wall.

Question 3

A home inspector observes cupping of asphalt shingles. What is the most likely cause?

Accepted Answer

Moisture imbalance causing the shingle edges to curl upward

Answer

Cupping occurs when shingle edges turn upward due to moisture differential between the top and bottom surfaces of the shingle.

Question 4

What condition does 'blistering' on an asphalt shingle roof indicate?

Accepted Answer

Trapped moisture or volatile compounds escaping from the shingle

Answer

Blistering results from trapped moisture or volatile compounds in the asphalt that vaporize and create raised bubbles on the shingle surface.

Question 5

Which type of roof deck material is most susceptible to delamination when exposed to prolonged moisture?

Accepted Answer

OSB (oriented strand board)

Answer

OSB is more susceptible to delamination and swelling from moisture exposure than plywood or solid lumber due to its composite wood fiber construction.

(InterNACHI) International Association of Certified Home Inspectors Practice Test

(InterNACHI) International Association of Certified Home Inspectors Practice Test

InterNACHI Roofing Systems and Components 2