Enter square footage calculate or enter the square footage of the attic or area to be vented.
Does my attic need more ventilation.
Homes do not have proper roof ventilation which can lead to severe roof damage.
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 downside of attic ventilation fans.
Roofing experts say the majority of u s.
Most building codes require 1 sq.
You can also contact your local municipality to check on building code in your area.
Most building codes require a ratio of 1 150 ventilation space to attic floor space.
Why roof ventilation is a must for example attic ventilation is used widely even in cold climates to evacuate the warm moist air that escapes from the living space below.
For the best results place roof ventilation near the roof s peak and soffit vents in the eaves.
So a house with a 1 500 sq ft.
Of venting technically net free vent area or nfva for each 150 sq.
Hvi recommends a ratio of 60 to 40 for soffit ventilation to gable or ridge ventilation.
Solar fans are powered by the sun so they don t require electricity to operate.
Attic will need 10 sq.
The federal housing administration recommends at least 1 square foot of ventilation for every 300 square feet of attic space.
If that air lingers it can cause condensation on the underside of the roof sheathing which can lead to wood rot and mold growth.
In other words the entire vent opening doesn t count as vented space.
Attic ventilation fans whether hard wired or powered by their own solar panels seem like a low cost and effective way to help keep your house cool.
Taking advantage of this natural process referred to as passive ventilation is the most common way to vent an attic.
Generally speaking you need a ratio of 1 300 where for every 300 square feet of ceiling space you need 1 square foot of 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.
In order to facilitate this exchange of warm and cool air the general rule of.
That said air resistance and interference such as vent grates reduces the area of true ventilation.
In some circumstances you can have less but we recommend the 1 150 ratio.
Of venting ideally about half placed high on the roof and half in the soffits.
Air flows in through the soffit vents and out through the roof vents.