Roof Sailing Roof Ventilation and Attic Systems 2

Question 1

What is the maximum recommended attic temperature for preserving asphalt shingle life during summer?

Accepted Answer

140°F

Answer

Industry guidelines suggest that attic temperatures above 140°F accelerate the thermal aging and granule loss of asphalt shingles; proper ventilation should keep peak attic temperatures below this threshold.

Question 2

What causes ice dams on roofs and how does proper ventilation help prevent them?

Accepted Answer

Ice dams form when heat escapes through the roof, melts snow, and refreezes at the cold eave; proper ventilation keeps the deck cold uniformly

Answer

Ice dams occur when attic heat warms the upper roof deck, melting snow that then refreezes at the cold eaves; proper ventilation removes attic heat so the entire deck stays uniformly cold, preventing the melt-refreeze cycle.

Question 3

What is the minimum clearance required between the tops of attic insulation and the roof deck sheathing for proper airflow?

Accepted Answer

1 inch

Answer

A minimum 1-inch clear airway between the top of the insulation and the underside of the roof deck sheathing must be maintained from eave to ridge to ensure adequate ventilation airflow.

Question 4

Which type of attic ventilation uses mechanical power to increase air exchange?

Accepted Answer

Powered attic ventilator (PAV)

Answer

A powered attic ventilator (PAV) uses an electric or solar-powered fan to actively draw hot air from the attic, providing much higher air exchange rates than passive vents alone.

Question 5

What ventilation problem occurs when both ridge vents and high gable vents are used together?

Accepted Answer

Short-circuiting — air flows directly from gable vent to ridge vent, bypassing the lower attic

Answer

When gable vents and ridge vents coexist, air takes the shortest path from gable to ridge, short-circuiting the system and leaving the lower attic unventilated where moisture and heat accumulate.

Roof Sailing Practice Test

Roof Sailing Practice Test

Roof Sailing Roof Ventilation and Attic Systems 2