Most building codes require a ratio of 1 150 ventilation space to attic floor space.
Roof ventilation requirements.
Feet of attic space divided 50 50 between the inlets and outlets.
The following are the requirements taken directly from the irc.
You can also contact your local municipality to check on building code in your area.
Measure the length and width of the attic floor space to be ventilated.
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 ventilation amount and opening size requirements can be found in section 806 roof ventilation of chapter 8 roof ceiling construction.
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.