GAF Ventilation & Attic Systems

Question 1

What is the minimum net free area (NFA) of ventilation required per 150 square feet of attic floor space when there is no vapor barrier?

Accepted Answer

1 square foot per 150 sq ft

Answer

Building codes typically require 1 square foot of NFA per 150 square feet of attic floor space when no vapor retarder is installed.

Question 2

Which type of attic ventilation system uses both soffit vents and a ridge vent to create airflow through natural convection?

Accepted Answer

Balanced ventilation system

Answer

A balanced ventilation system pairs soffit (intake) vents with ridge (exhaust) vents so cool air enters low and hot air exits high via natural convection.

Question 3

GAF's Cobra® Ridge Vent products are designed primarily to function as which component of attic ventilation?

Accepted Answer

Exhaust ventilation

Answer

GAF Cobra® Ridge Vents are exhaust ventilation products installed at the ridge to allow hot, moist air to escape from the attic.

Question 4

What problem can result from having more exhaust ventilation capacity than intake ventilation capacity in an attic?

Accepted Answer

Short-circuiting where air is pulled in through exhaust vents

Answer

When exhaust exceeds intake, the system can short-circuit by drawing outside air back in through the exhaust vents rather than pulling it from the soffits.

Question 5

According to proper ventilation principles, what percentage of the total NFA should be allocated to intake vents versus exhaust vents?

Accepted Answer

50% intake, 50% exhaust

Answer

Best practice is a 50/50 balanced split between intake and exhaust net free area to ensure proper airflow through the attic.

(GAF) GAF Certified Roofing Contractors Practice Test

(GAF) GAF Certified Roofing Contractors Practice Test

GAF Ventilation & Attic Systems