How Many Roof Vents Required

Of net free area of exhaust needed at or near the ridge.

How many roof vents required.

Of course there should be intake vents to ensure a balanced system. A roof vent is a type of fixture installed on your roof that exhausts hot air. Figure 7 mechanical ventilation used with a hip roof. For the number of soffit vents in the example divide 8 square feet of ventilation needed by 0 5 for the number of rectangular vents required 16 in the example.

Taking advantage of this natural process referred to as passive ventilation is the most common way to vent an attic. One method is to use a powered attic vent with a humidistat thermostat located close to the ridge or top of the roof. Advantages of proper roofing ventilation. Proper attic ventilation offers numerous advantages to the homeowner.

Attic ventilation requirements how many attic vents your roof needs industry standard for proper attic ventilation recommends for no vapor retarder type of attic insulation no paper plastic or aluminum layer between the attic floor and insulation layer 1 sq. Foot of ventilation for every 150 sq. One of the easiest and most. Hot air exhaust vents located at the peak of the roof allow hot air to escape.

Ridge static attic vents 384 00 minimum sq. Ventsure 4 foot strip heat moisture ridge vent. Proper attic ventilation consists of a balance between air intake at your eaves soffits or fascias and air exhaust at or near your roof ridge. Now you know how many square inches of attic roof venting you need for the roof and soffit.

27 lineal feet required. The size of your roof and attic space will determine how many roof vents you need. Although there are many different types of roof vents to choose from ensuring you have the right number of both intake and exhaust vents is a central part of roof design. For the 1 150 attic ventilation requirement simply double the amount of exhaust and intake calculated.

This calculator gives you the required attic ventilation requirement. Choose one of the following products to meet the recommended exhaust nfva of 528 square inches. Federal housing authority recommends a minimum of at least 1 square foot of attic ventilation evenly split between intake and exhaust for every 300 square feet of attic floor space. Next divide that number by 2.

In our case the required 4 vents for the 1200 sq ft house multiply the 144 cubic inches by 4 576 cubic inches. Feet of attic space divided 50 50.