CHI CHI Roofing Systems Inspection 1 — Questions and Answers
Question 1: When inspecting an asphalt shingle roof, which defect indicates the shingles have reached the end of their service life?
- Minor granule loss in gutters during initial installation
- Cupping, curling, or clawing of the shingle tabs (Correct answer)
- Slight color variation between shingle rows
- Nail heads that are slightly visible at the shingle surface
Correct answer: Cupping, curling, or clawing of the shingle tabs
Cupping (edges turning upward), curling (edges turning downward), and clawing (middle lifting while edges stay flat) are all signs of advanced aging and thermal cycling fatigue in asphalt shingles.
Question 2: A home inspector identifies open step flashing where a roof plane meets a sidewall. What is the primary risk of this deficiency?
- Accelerated granule loss on adjacent shingles
- Water infiltration into the wall assembly and interior (Correct answer)
- Premature oxidation of the roofing fasteners
- Reduced wind uplift resistance of the roof covering
Correct answer: Water infiltration into the wall assembly and interior
Open or improperly lapped step flashing creates a direct pathway for wind-driven rain to enter the wall-to-roof junction and damage sheathing, insulation, and interior finishes.
Question 3: What is the minimum roof slope typically required for standard three-tab asphalt shingles to be installed without special underlayment modifications?
- 1:12
- 2:12
- 3:12 (Correct answer)
- 4:12
Correct answer: 3:12
Standard asphalt shingles require a minimum 3:12 slope; below this pitch, water drains too slowly and can back up under shingle laps, causing leaks.
Question 4: During a roof inspection, the home inspector observes black streaking running down the shingles. What is the most likely cause?
- Oil bleeding from the asphalt matrix
- Algae (Gloeocapsa magma) growth (Correct answer)
- Oxidation of the zinc strips at the ridge
- Chimney tar deposits washing down in rain
Correct answer: Algae (Gloeocapsa magma) growth
Dark streaks on asphalt shingles are almost always caused by Gloeocapsa magma, a blue-green algae that feeds on the limestone filler in shingles and leaves a dark protective pigment.
Question 5: Which type of underlayment is required by most US building codes in the first 24 inches from the eave on roofs in cold climates?
- 15-lb felt paper
- 30-lb felt paper
- Ice and water shield (self-adhering membrane) (Correct answer)
- Synthetic non-woven polypropylene underlayment
Correct answer: Ice and water shield (self-adhering membrane)
Ice-and-water shield (self-adhering modified bitumen membrane) is required at the eave to protect against water backup caused by ice dams in cold climates.
Question 6: A home inspector finds that a roof valley is using the 'open valley' method with metal flashing. What minimum width of exposed metal is generally recommended for proper function?
- 2 inches total (1 inch per side)
- 6 inches total (3 inches per side) (Correct answer)
- 12 inches total (6 inches per side)
- 18 inches total (9 inches per side)
Correct answer: 6 inches total (3 inches per side)
Open metal valleys should expose at least 3 inches of flashing on each side (6 inches total) to direct water safely down the valley without reaching shingle laps.
CHI CHI Roofing Systems Inspection 1
When inspecting an asphalt shingle roof, which defect indicates the shingles have reached the end of their service life?