How Many Vents Does My Roof Need

Even if you have vents in your roof you still need to have soffit vents to allow the air to circulate naturally.

How many vents does my roof need.

Of net free area of exhaust needed at or near the ridge. I have roof vents so i have roof ventilation. Federal housing authority recommends a minimum of at least 1 square foot of attic ventilation for every 300 square feet of attic floor space evenly split between intake and exhaust. A single 14 inch diameter turbine vent that is subjected to 15 mph winds can expel up to 1 342 cfm of air.

As a general rule your roof needs 1 square foot of vent area for every 150 square feet of attic space. There are a number of different types of vents to choose from so getting the ones to suit you should not be difficult although you will still need to work out how many to purchase. Soffit vents are vital in keeping air flowing throughout your attic space. Click here to get free fast bids from local roofers who can install turbine vents.

Let owens corning roofing help you calculate exactly how much ventilation you will need for a healthy and balanced attic with our 4 step ventilation calculator. These specialty vents do not affect the. Rafter vents or insulation baffles install in any rafter space to create narrow gaps that direct fresh air from the soffit vents to the peak of the roof. Other types there are also several other types of roof vents including dome or box shaped vents that run through the roof itself.

The first step in determining how many vents you need is to calculate the net free area nfa required. If the winds are still the vents still allow air to drift up and out of the attic space although not nearly as much. This means that for every 300 square feet of enclosed attic space 1 square foot of ventilation is required with half at the upper portion exhaust. Roofing resources during.

Ventsure 4 foot strip heat moisture ridge vent. Of net free area of intake needed at or near the soffit. The majority of roofing experts agree that ridge vents are the most effective and cost effective roof vents available. Thus if your attic is 450 square feet you need roof vents equaling 3 square feet.

Most codes use the 1 300 rule for minimum residential attic ventilation recommendations. They should be divided equally between inlet and outlet vents and they can be used in any combination that will work with your roof s design. For the 1 150 attic ventilation requirement simply double the amount of exhaust and intake calculated. Take for example ridge vents.

How many vents do i need. How many vents will my house need. Watch my video below. Choose one of the following products to meet the recommended exhaust nfva of 528 square inches.