Number Of Roof Vents Required

Now you know how many square inches of attic roof venting you need for the roof and soffit.

Number of roof vents required.

The next step is to select a suitable exhaust vent and intake vent that fits the roof design for best performance and best aesthetics. Multiple these two. Eac 16x8 metal soffit vents. It s time to install.

Based on your 1100 sq. Measure the length and width of the attic space using a tape measure. Thus if your attic is 450 square feet you need roof vents equaling 3 square feet. The calculations before indicated that we needed 2 square feet of ridge or upper roof ventilation.

Federal housing authority recommends a minimum of at least 1 square foot of attic ventilation for every 300 square feet of attic floor space evenly split between intake and exhaust. So we would need at least six metal vents in addition to the lower soffit ventilation to meet minimum ventilation requirements. After that find out the vent s nfa as rated by the manufacturer. 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.

Foot of ventilation for every 150 sq. A normal metal pot vent produces only 50 squares inches of free net area. Near ridge of the roof. The federal housing administration recommends 1 square foot of attic.

Two square feet equals 288 square inches. As a general rule your roof needs 1 square foot of vent area for every 150 square feet of attic space. Eac 16x4 metal soffit vents. How to determine the number of attic vents.

Embershield closeable soffit vents. Calculate the square footage of your attic. And this guideline you ll need a minimum of. Lsv8 metal continuous soffit vents lineal feet 31 eap 4x12 plastic soffit vents.

They should be divided equally between inlet and outlet vents and they can be used in any combination that will work with your roof s design. Divide the attic s square footage by 150. Next divide that number by 2. Use the calculator below to find out how many exhaust and intake vents you will need on your house.

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