Estimating Ventilation Requirements For Attic

Intake vents located at the lowest part of the roof under the eaves allow cool.

Estimating ventilation requirements for attic.

Ridge vents are one of the easiest ways to meet roof venting requirements. Prior to installing the ridge vent a 1 inch wide strip of roof decking is cut out along both sides of the ridgeline to allow for air movement through the vent. Typically building codes include minimum requirements applicable to attic ventilation. Foot of ventilation for every 150 sq.

Feet of attic space divided 50 50. The open area of a vent is sometimes listed on the roof air vent as nfva net free vent area. In of vent opening per 150 sq. The roofing industry also has practical guide lines for attic ventilation.

Then aim for about 1 sq. Generally as the roof pitch increases the volume inside the attic also increases along with the amount of needed. Standard attic vents like af 50 s ventilation fans or solar powered attic fans. Proper attic ventilation can be an impor tant performance consideration when design ing and installing steep slope roof systems.

It is important that air movement occurs and is not impeded by any framing members of the. 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. Calculating attic ventilation requirements. Enter square footage calculate or enter the square footage of the attic or area to be vented.

Code requirements the international building code. A ridge vent is a ventilation strip that is placed along the ridgeline of the home. Hence you would need two square feet 600 300 of attic ventilation. Other options to meet your attic ventilation needs are.

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. Result of item 1 300. Calculate the square footage of the attic space. Attic ventilation works on the principle that heated air naturally rises primarily utilizing two types of vents.

Divide the square footage item 1 by 300. The ridge vent is installed on the peak with nails and shingled over for aesthetic purposes. The building code lets you reduce that by half under some conditions but more roof ventilation is usually better. Proper attic ventilation consists of a balance between air intake at your eaves soffits or fascias and air exhaust at or near your roof ridge.

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.