How Many Roof Vents Required

Ventsure 4 foot strip heat moisture ridge vent.

How many roof vents required.

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. 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. One method is to use a powered attic vent with a humidistat thermostat located close to the ridge or top of the roof. 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.

Luckily there is a basic formula you can use to determine this. Ridge static attic vents 384 00 minimum sq. Next divide that number by 2. For the 1 150 attic ventilation requirement simply double the amount of exhaust and intake calculated.

One of the easiest and most. And in many of these cases the hip roof forms a large volumetric attic space to ventilate. A roof vent is a type of fixture installed on your roof that exhausts hot air. Taking advantage of this natural process referred to as passive ventilation is the most common way to vent an attic.

Of net free area of intake needed at or near the soffit. In our case the required 4 vents for the 1200 sq ft house multiply the 144 cubic inches by 4 576 cubic inches. Hot air exhaust vents located at the peak of the roof allow hot air to escape. Now you know how many square inches of attic roof venting you need for the roof and soffit.

Proper attic ventilation offers numerous advantages to the homeowner. Choose one of the following products to meet the recommended exhaust nfva of 528 square inches. Advantages of proper roofing ventilation. Feet of attic space divided 50 50.

27 lineal feet required. This calculator gives you the required attic ventilation requirement. Of course there should be intake vents to ensure a balanced system. Of net free area of exhaust needed at or near the ridge.

Figure 7 mechanical ventilation used with a hip roof. The size of your roof and attic space will determine how many roof vents you need.