Required Ventilation In Attic

Federal housing authority recommends a minimum of at least 1 square foot of attic ventilation evenly split between intake and exhaust for every 300 square feet of attic floor space.

Required ventilation in attic.

Intake vents located at the lowest part of the roof under the eaves. You can also contact your local municipality to check on building code in your area. 30 lineal feet required. Calculate or enter the square footage of the attic or area to be vented.

Furthermore nrca also rec ommends the amount of ventila. The following is an example shown in the irc commentary for a simple gable roof using the 1 300 ratio. Let owens corning roofing help you calculate exactly how much ventilation you will need for a healthy and balanced attic with our 4 step ventilation calculator. For large volume attics such as where roof slopes are greater than 8 12 designers also should consider increasing the amount of attic ventilation to account for the additional volume of attic space.

Of attic space 1 150 ventilation ratio measured at the attic floor level ceiling. Attic ventilation works on the principle that heated air naturally rises primarily utilizing two types of vents. Ventilation of attic spaces is required by most building codes as well as by roofing material manufacturers and the national roofing contractors association nrca.