Roof Space Ventilation Requirements

The air gap dimensions shown on the drawings are the minimum widths required for clear continuous ventilation air paths at the eaves.

Roof space ventilation requirements.

In order to facilitate this exchange of warm and cool air the general rule of thumb suggests installing at least 1 sq. Roof vents choose one of the following products to meet the recommended exhaust nfva of 528 square inches. As an example in an attic that is 30 feet by 20 feet you would have 600 square feet of floor area. Of vent for every 300 sq.

Roof voids must be ventilated in order to stop warm air condensing on cold surfaces. Measure the length and width of the attic floor space to be ventilated. Proper attic area ventilation is an important performance consideration for a home or building with a steep slope roof. Building codes vary.

According to the fha federal housing administration us for every 300 square feet of attic floor area you should have at minimum one square foot ventilation. The key to proper ventilation of your roof and attic is balance. This pk topic provides commonly accepted ventilation practices compatible with a decra roof system installation. Ventilation at the eaves.

Ventilation of attic spaces is required by most building codes as well as by roofing material manufacturers and the national roofing contractors association nrca. There should also be a 50 50 balance of attic venting and roof venting. According to the national roofing contractors association nrca a power vent with an airflow rate of 1 0 cubic foot per minute per square foot of attic space measured at the attic floor is generally considered to be equivalent to a 1 150 ventilation ratio. Ventsure 4 foot strip heat moisture ridge vent 27 lineal feet required.

Most building codes require a ratio of 1 150 ventilation space to attic floor space. If your roof is 1200 sq ft soffit floor space you will need 4 sq feet of roof ventilation. According to their requirements you should have 1 square foot of attic ventilation per 300 sq ft of attic floor space. Typically building codes include minimum attic space ventilation requirements as well as the roofing industry weighing in on practical guidelines.

You can also contact your local municipality to check on building code in your area. Hence you would need two square feet 600 300 of attic ventilation.