Roof Sailing Knowledge 5 — Questions and Answers
Question 1: Which roofing system uses interlocking panels that expand and contract with temperature changes without buckling?
- Built-up roofing (BUR)
- Standing seam metal roofing (Correct answer)
- EPDM membrane roofing
- Modified bitumen roofing
Correct answer: Standing seam metal roofing
Standing seam metal roofing uses concealed clips that allow panels to float and move freely with thermal expansion and contraction.
Question 2: What causes blistering on asphalt shingles?
- Improper nailing depth driving nails too deep
- Trapped moisture or volatile gases expanding during heating (Correct answer)
- UV exposure breaking down the asphalt binder
- Ice dam pressure lifting the shingle surface
Correct answer: Trapped moisture or volatile gases expanding during heating
Blistering occurs when moisture or trapped gases within the shingle expand under heat, forming raised bubbles on the surface.
Question 3: In a balanced ventilation system, what percentage of the total vent area should be intake (soffit) vents?
- 25%
- 50% (Correct answer)
- 75%
- 100%
Correct answer: 50%
A balanced system splits vent area equally — 50% intake at the soffits and 50% exhaust at the ridge — for optimal airflow.
Question 4: What is the correct nail placement zone (nail line) on a standard three-tab shingle?
- 1 inch above the cutouts
- In the sealant strip area above the tabs
- At the manufacturer's marked nail line, typically 5/8 inch above the cutout top (Correct answer)
- At the very top edge of the shingle
Correct answer: At the manufacturer's marked nail line, typically 5/8 inch above the cutout top
Nails must be driven at the manufacturer's specified nail line, usually 5/8 inch above the top of the cutouts, to ensure fasteners hold properly through all shingle layers.
Question 5: Which condition should a roofer look for to identify an active ice dam on a roof?
- Missing granules near the ridge
- Icicles forming at the eave with water staining on interior ceilings (Correct answer)
- Moss growing along the north-facing slope
- Lifted shingles along the rake edge
Correct answer: Icicles forming at the eave with water staining on interior ceilings
Ice dams form when heat escapes through the upper roof and melts snow; water refreezes at the cold eave and backs up under shingles, causing interior staining.
Question 6: When re-roofing over an existing layer of shingles, what is typically the maximum number of layers allowed by most building codes?
- 1 layer total
- 2 layers total (Correct answer)
- 3 layers total
- 4 layers total
Correct answer: 2 layers total
Most building codes limit roofs to two total layers of asphalt shingles before a full tear-off is required, due to weight and inspection concerns.
Question 7: Which property of a Class A fire-rated roofing assembly indicates?
- The assembly is immune to hail damage
- The assembly provides the highest resistance to fire spread from external sources (Correct answer)
- The assembly meets minimum wind uplift resistance
- The assembly is approved for low-slope applications only
Correct answer: The assembly provides the highest resistance to fire spread from external sources
Class A is the highest fire rating for roofing, indicating the assembly is highly resistant to severe fire exposure from external sources such as burning embers.
Roof Sailing Knowledge 5
Which roofing system uses interlocking panels that expand and contract with temperature changes without buckling?