How To Figure Roof Venting Requirements

Hit the calculate button for the recommended amount of exhaust and intake ventilation.

How to figure roof venting requirements.

The ventilation amount and opening size requirements can be found in section 806 roof ventilation of chapter 8 roof ceiling construction. Ventilation of attic spaces is required by most building codes as well as by roofing material manufacturers and the national roofing contractors association nrca. Result of item 1 300. If your roof is 1200 sq ft soffit floor space you will need 4 sq feet of roof ventilation.

Ft you divide that by 150 to get 10 sq. The rule of thumb on the amount of vent space needed is approximately 1 sq. Standard ridge vent produces 18 square inches of ventilating area per lineal foot. Based on your 1100 sq.

Next multiply the 4 square feet into cubic inches. Measure the length and width of the attic floor space to be ventilated. Near ridge of the roof. Most building codes require a ratio of 1 150 ventilation space to attic floor space.

The majority of the requirements related to attic ventilation have not changed much from the previous editions. In order to find the right calculator divide the attic floor space by 300 sq feet. And this guideline you ll need a minimum of. So if your attic is 1 500 sq.

Enter the length and width of the attic floor or the total square footage of the attic floor. You can also contact your local municipality to check on building code in your area. Change the square feet to square inches. Calculate the square footage of the attic space.

See quantities below for each gaf ventilation product typically rounded up. Our roof is 50 feet long so using a standard product we will get 900 square inches of ventilating space. Divide the square inches by 2. Result of item 3 2.

So the ridge ventilation has exceeded the minimum requirement. 1 cubic foot is 12 x 12 144 cubic inches. Calculating attic ventilation requirements. Nine hundred square inches equals 6 25 square feet.

Divide the square footage item 1 by 300.