Calculate the square footage of the attic space.
Attic ventilation requirements.
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.
Attic ventilation is an important part of keeping your building healthy.
The following are the requirements taken directly from the irc.
Proper attic ventilation can be an impor tant performance consideration when design ing and installing steep slope roof systems.
Foot of ventilation for every 150 sq.
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.
Standard attic vents like af 50 s ventilation fans or solar powered attic fans.
Calculating attic ventilation requirements.
Hence you would need two square feet 600 300 of attic ventilation.
The majority of the requirements related to attic ventilation have not changed much from the previous editions.
Feet of attic space divided 50 50 between the inlets and outlets.
The two square feet is divided equally between the intake and the exhaust one square foot for each.
Other options to meet your attic ventilation needs are.
Ridge vents are one of the easiest ways to meet roof venting requirements.
Current regulations state that the minimum attic ventilation requirements are 150 1.
Divide the square footage item 1 by 300.
This means that if you have a 1500 sq attic then you would need at least 10 sf of ventilation.
Most building codes require a ratio of 1 150 ventilation space to attic floor space.
Choose one of the following products to meet the recommended intake nfva of 528 square inches.
The ventilation amount and opening size requirements can be found in section 806 roof ventilation of chapter 8 roof ceiling construction.
Allows cool dry air to enter the attic.
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.
Intake vents located at the lowest part of the roof under the eaves allow cool.
Typically building codes include minimum requirements applicable to attic ventilation.
Attic ventilation works on the principle that heated air naturally rises primarily utilizing two types of vents.
The ridge vent is installed on the peak with nails and shingled over for aesthetic purposes.
Ventilation of attic spaces is required by most building codes as well as by roofing material manufacturers and the national roofing contractors association nrca.
The following product options will allow you to achieve an intake nfva of 528 square inches.
