How Many Roof Vents Should You Have

Taking advantage of this natural process referred to as passive ventilation is the most common way to vent an attic.

How many roof vents should you have. In of vent opening per 150 sq. Then aim for about 1 sq. Solid vinyl soffit material costs the same as the vented material. Foot of ventilation for every 150 sq.

You ll need the square footage of your attic to calculate the number of roof vents that you should need. Hot air exhaust vents located at the peak of the roof allow hot air to escape. 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. As a general rule your roof needs 1 square foot of vent area for every 150 square feet of attic space.

First determine your attic area by multiplying the length by the width. 8 perform similar calculations for the roof and ridge vents. With any attic ventilation system the attic can be 20 degrees hotter than outside. 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.

Then you can begin choosing the style and type of roof vents you want for your home. For example if you have 1200 square feet of attic space you should need at least 4 air vents to ensure proper ventilation. Feet of attic space divided 50 50. It s important to remember that it s better to have too much intake ventilation than too little and many homes often undercalculate the amount of intake needed so worry less about having too much intake and err on the side of having more.

Attic for example has an area of 1 200 sq. A 30 x 40 ft. Enter square footage calculate or enter the square footage of the attic or area to be vented. Thus if your attic is 450 square feet you need roof vents equaling 3 square feet.

The building code lets you reduce that by half under some conditions but more roof ventilation is usually better. If the home already has a fan roof vents or gable vents these should be blocked and sealed from the attic side of the home. Attic ventilation requirements how many attic vents your roof needs.