In the article above it says the totalvent area for an attic should equal one square foot of vent space for every 150 square feet of attic area.
How many soffit vents in attic.
Attic will need 10 sq.
Enter square footage calculate or enter the square footage of the attic or area to be vented.
Divide the square footage by 150 to calculate the area of ventilation needed since you need 1 square foot of vent space for each 150 square feet of attic space.
Most building codes require 1 sq.
For the number of soffit vents in the example divide 8 square feet of ventilation needed by 0 5 for the number of rectangular vents required 16 in the example.
This ratio is required for modern insulated homes.
For example you might have to place one soffit vent and one other kind of vent for each 150 sq.
Of venting ideally about half placed high on the roof and half in the soffits.
If you have 3 000 square feet of attic space this equates to 20 square feet of ventilation needed.
So a house with a 1 500 sq ft.
Soffit vents help increase the airflow are easy to install and only cost about 3 per 8 ft.
Measure your attic the building requirements will probably tell you to place a certain number of soffit vents per square foot of ceiling space.
Choosing round soffit vents for.
That number is then divided by 2 so that half 1 300 of the vent area is in the soffit vents and half 1 300 is in the ridge vents which is what is called for in r806 2.
In some circumstances you can have less but we recommend the 1 150 ratio.
The ideal roof attic ventilation would consists of combination of vents located in upper section of the attic ridge vents turbine box shaped or dome static vents electric motor powered vents vents installed along the bottom parts of the roof overhang called intake or soffit vents hip vents and or gable vents all of the provided.
We show you how to install soffit vents step by step to improve your attic ventilation.
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.
Almost all homes are fitted with some kind of roof vents at the peak of the roofline be it individual roof vents hip roof ventilation and many homes have gable vents as well.