How To Figure Roof Venting Requirements

See quantities below for each gaf ventilation product typically rounded up.

How to figure roof venting requirements. Result of item 2 x 144. Near ridge of the roof. Result of item 3 2. The ventilation amount and opening size requirements can be found in section 806 roof ventilation of chapter 8 roof ceiling construction.

The rule of thumb on the amount of vent space needed is approximately 1 sq. Measure the length and width of the attic floor space to be ventilated. Ft you divide that by 150 to get 10 sq. Standard ridge vent produces 18 square inches of ventilating area per lineal foot.

Result of item 1 300. Of vent space for every 150 sq. Calculate the square footage of the attic space. Calculating attic ventilation requirements.

Hit the calculate button for the recommended amount of exhaust and intake ventilation. Change the square feet to square inches. If your roof is 1200 sq ft soffit floor space you will need 4 sq feet of roof ventilation. Nine hundred square inches equals 6 25 square feet.

Ventilation of attic spaces is required by most building codes as well as by roofing material manufacturers and the national roofing contractors association nrca. So if your attic is 1 500 sq. So the ridge ventilation has exceeded the minimum requirement. The majority of the requirements related to attic ventilation have not changed much from the previous editions.

Based on your 1100 sq. You can also contact your local municipality to check on building code in your area. Most building codes require a ratio of 1 150 ventilation space to attic floor space. And this guideline you ll need a minimum of.

Enter the length and width of the attic floor or the total square footage of the attic floor. Our roof is 50 feet long so using a standard product we will get 900 square inches of ventilating space. The following are the requirements taken directly from the irc. Divide the square footage item 1 by 300.

1 cubic foot is 12 x 12 144 cubic inches.