Roof Ventalation Requirements

You can calculate attic ventilation requirements by determining the square footage of your attic floor its width times its length and compare that to the total required net free area nfa.

Roof ventalation requirements.

Feet of attic space divided 50 50 between the inlets and outlets. Ventilation of attic spaces is required by most building codes as well as by roofing material manufacturers and the national roofing contractors association nrca. Ventsure 4 foot strip heat moisture ridge vent 27 lineal feet required. The key to proper ventilation of your roof and attic is balance.

Foot of ventilation for every 150 sq. Attic ventilation requirements how many attic vents your roof needs industry standard for proper attic ventilation recommends for no vapor retarder type of attic insulation no paper plastic or aluminum layer between the attic floor and insulation layer 1 sq. Roof vents choose one of the following products to meet the recommended exhaust nfva of 528 square inches. Most building codes require a ratio of 1 150 ventilation space to attic floor space.

R806 1 ventilation required enclosed attics and enclosed rafter spaces formed where ceilings are applied directly to the underside of roof rafters shall have cross ventilation for each separate space by ventilating openings protected against the entrance of rain or snow.