Roofing Systems and Components Flashcards

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

Answer: 2:12

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

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

Answer: Step flashing

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

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

Answer: Moisture imbalance causing the shingle edges to curl upward

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

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

Answer: Trapped moisture or volatile compounds escaping from the shingle

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

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

Answer: OSB (oriented strand board)

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

When inspecting a roof, an inspector finds granules accumulating in the gutters. What does this most likely indicate?

Answer: The shingles are approaching end of useful life

Significant granule loss in gutters typically indicates shingles are aging and losing their protective coating, signaling they are near the end of their service life.

What is the purpose of a cricket (saddle) installed behind a chimney?

Answer: To divert water around the chimney and prevent ponding

A cricket is a peaked saddle structure built behind wide chimneys to redirect water away and prevent it from pooling against the chimney base.