Does My Attic Need More Ventilation

Hvi recommends a ratio of 60 to 40 for soffit ventilation to gable or ridge ventilation.

Does my attic need more ventilation.

Enter square footage calculate or enter the square footage of the attic or area to be vented. Most building codes require a ratio of 1 150 ventilation space to attic floor space. Ventilation of attic spaces is required by most building codes as well as by roofing material manufacturers and the national roofing contractors association nrca. Air flows in through the soffit vents and out through the roof vents.

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. If that air lingers it can cause condensation on the underside of the roof sheathing which can lead to wood rot and mold growth. 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. In some circumstances you can have less but we recommend the 1 150 ratio.

Of venting technically net free vent area or nfva for each 150 sq. 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. That said air resistance and interference such as vent grates reduces the area of true ventilation. In order to facilitate this exchange of warm and cool air the general rule of.

The downside of attic ventilation fans. In other words the entire vent opening doesn t count as vented space. Because this type of fan blows so much hot air out of the attic it often requires additional intake ventilation to replace the air such as a gable vent on the opposite side of the attic. Most building codes require 1 sq.

Roofing experts say the majority of u s. Homes do not have proper roof ventilation which can lead to severe roof damage. 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. Of venting ideally about half placed high on the roof and half in the soffits.

Attic will need 10 sq. Solar fans are powered by the sun so they don t require electricity to operate. You can also contact your local municipality to check on building code in your area. Grab a flashlight and inspect your attic during the winter.

Taking advantage of this natural process referred to as passive ventilation is the most common way to vent an attic. If you see dampness or frost you need better roof ventilation and some attic vents.