Home Inspector Roofing Systems and Materials Questions and Answers — Questions and Answers
Question 1: During a winter inspection in a cold climate, you observe a significant ridge of ice along the eaves of a home. This is most likely caused by:
- Clogged gutters and downspouts.
- Lack of a self-adhering ice and water shield membrane.
- Heat loss from the house into the attic, melting snow on the upper roof. (Correct answer)
- Excessively high winds blowing snow onto the roof edge.
Correct answer: Heat loss from the house into the attic, melting snow on the upper roof.
Ice dams form when heat escapes from the living space into the attic, warming the underside of the roof deck. This causes snow on the upper portion of the roof to melt. The meltwater then runs down to the colder eaves, where it refreezes, creating a dam of ice.
Question 2: While inspecting a recently installed asphalt shingle roof, you notice some shingles have circular marks with missing granules and a soft or bruised feel to the touch. Which of the following is the most probable cause of this condition?
- Hail impact. (Correct answer)
- Blistering from manufacturing defects.
- Normal weathering and aging.
- Scuffing from foot traffic during installation.
Correct answer: Hail impact.
Hail damage on asphalt shingles often presents as random, circular bruises or dents where granules have been knocked off, exposing the underlying asphalt. These impact points often feel soft or spongy to the touch, similar to a bruised apple.
Question 3: A home inspector is evaluating the attic of a 1,800-square-foot house. According to the standard International Residential Code (IRC) 1/150 rule, what is the minimum required net free ventilating area (NFVA)?
- 6 square feet
- 10 square feet
- 12 square feet (Correct answer)
- 15 square feet
Correct answer: 12 square feet
The standard IRC rule for attic ventilation is 1 square foot of net free ventilating area for every 150 square feet of attic floor space. Therefore, for an 1,800-square-foot attic, the calculation is 1800 / 150 = 12 square feet of NFVA.
Question 4: Which of the following materials is commonly used for roof flashing due to its durability, malleability, and corrosion resistance, often developing a distinctive green patina over time?
- Galvanized Steel
- Aluminum
- PVC (Polyvinyl Chloride)
- Copper (Correct answer)
Correct answer: Copper
Copper is a premium flashing material known for its long-term durability, excellent malleability for complex shapes, and superior resistance to corrosion. Over time, it develops a characteristic and protective green patina.
Question 5: A home inspector identifies a Built-Up Roofing (BUR) system on a commercial flat roof. When properly installed and maintained with multiple plies, what is the typical life expectancy of this type of roofing system?
- 5-10 years
- 10-15 years
- 20-30 years (Correct answer)
- 40-50 years
Correct answer: 20-30 years
A properly installed and maintained Built-Up Roofing (BUR) system, which consists of multiple layers of bitumen and reinforcing fabrics, typically has a life expectancy of 20 to 30 years. The number of layers (plies) directly impacts its longevity.
Question 6: According to the National Roofing Contractors Association (NRCA), what is the recommended minimum slope for the application of standard asphalt shingles?
- 2:12
- 3:12
- 4:12 (Correct answer)
- 5:12
Correct answer: 4:12
While some building codes and manufacturers may permit asphalt shingles on slopes as low as 2:12 with special underlayment, the NRCA recommends a minimum slope of 4:12 for asphalt shingle installations to ensure proper water shedding.
Home Inspector Roofing Systems and Materials Questions and Answers
During a winter inspection in a cold climate, you observe a significant ridge of ice along the eaves of a home.
This is most likely caused by: