Roof Sailing Roof Sailing MCQ 5 — Questions and Answers
Question 1: What is 'step flashing,' and where is it primarily used?
- Flat metal strips used along ridges
- L-shaped metal pieces installed in courses where a vertical wall meets a sloped roof (Correct answer)
- Rubber boots used around pipe penetrations
- Continuous metal strips along the eave
Correct answer: L-shaped metal pieces installed in courses where a vertical wall meets a sloped roof
Step flashing consists of individual L-shaped metal pieces interwoven with shingle courses to waterproof the joint where a sloped roof meets a vertical wall.
Question 2: Which condition most commonly causes a roof to fail its inspection after a roof sailing project?
- Shingles that are too colorful
- Improper nail placement outside the manufacturer's nail zone (Correct answer)
- Using a pneumatic nailer instead of a hammer
- Installing ridge vents
Correct answer: Improper nail placement outside the manufacturer's nail zone
Nails placed outside the designated nail zone — too high or too low — can cause shingle blow-off and void manufacturer warranties, leading to inspection failure.
Question 3: What does the term 'starter strip' refer to in roofing?
- The first course of underlayment
- A specially cut or pre-manufactured shingle installed at the eave and rake before the first full shingle course (Correct answer)
- The bottom row of ridge caps
- Metal drip edge installed at the gutter
Correct answer: A specially cut or pre-manufactured shingle installed at the eave and rake before the first full shingle course
A starter strip is installed at the eave and rake edges to seal the first course of shingles and prevent wind uplift at the most vulnerable roof edge.
Question 4: A roof sailor is working near a skylight curb. What is the correct way to flash around a raised skylight curb?
- Apply roofing cement only
- Install head, side, and sill flashing with counter-flashing over the curb cap (Correct answer)
- Wrap the curb with self-adhering membrane only
- Install step flashing on all four sides without counter-flashing
Correct answer: Install head, side, and sill flashing with counter-flashing over the curb cap
Proper skylight curb flashing requires base flashing (head, sides, sill) integrated with shingles and counter-flashing over the curb cap to create a fully weathertight system.
Question 5: What is the purpose of a drip edge on a roof?
- To increase attic ventilation
- To direct water away from the fascia and into the gutter (Correct answer)
- To hold the first course of shingles flat
- To anchor the eave underlayment
Correct answer: To direct water away from the fascia and into the gutter
Drip edge is a metal flashing installed at the eave and rake that directs water away from the fascia board and into the gutter, preventing wood rot.
Question 6: When using a nail gun on a roof, what setting should be checked to prevent over-driving nails into shingles?
- Compressor tank size
- Air pressure and depth-of-drive adjustment (Correct answer)
- Nail magazine capacity
- Trigger mode (sequential vs. contact)
Correct answer: Air pressure and depth-of-drive adjustment
Adjusting air pressure and the depth-of-drive dial ensures nails are driven flush with the shingle surface without cutting through the mat, which compromises holding strength.
Question 7: Which attic ventilation ratio is required by most US building codes when no vapor barrier is present?
- 1:600 (1 sq ft of net free vent area per 600 sq ft of attic floor)
- 1:150 (1 sq ft of net free vent area per 150 sq ft of attic floor) (Correct answer)
- 1:300 (1 sq ft of net free vent area per 300 sq ft of attic floor)
- 1:1000 (1 sq ft of net free vent area per 1000 sq ft of attic floor)
Correct answer: 1:150 (1 sq ft of net free vent area per 150 sq ft of attic floor)
IRC requires a 1:150 net free vent ratio when no vapor retarder is installed, ensuring sufficient airflow to prevent moisture buildup and extend roof system life.
Roof Sailing Roof Sailing MCQ 5
What is 'step flashing,' and where is it primarily used?