Roof Ventilation Requirements

Feet of attic space divided 50 50 between the inlets and outlets.

Roof ventilation requirements.

Roof vents choose one of the following products to meet the recommended exhaust nfva of 528 square inches. 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. Ventsure 4 foot strip heat moisture ridge vent 27 lineal feet required. The following are the requirements taken directly from the irc.

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. You can also contact your local municipality to check on building code in your area. 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.

Measure the length and width of the attic floor space to be ventilated.