Attic Ventilation Needs

That said air resistance and interference such as vent grates reduces the area of true ventilation.

Attic ventilation needs. If you see dampness or frost you need better roof ventilation and some attic vents. Lowering the temperature in the attic can help reduce air conditioning energy costs and roof deck temperature optimize the service life of a roof covering and minimize ice damming. Ventilation of attic spaces is required by most building codes as well as by roofing material manufacturers and the national roofing contractors association nrca. Vents come in various styles.

And this guideline you ll need a minimum of. To lower attic temperatures and to remove excess moisture. Moreover if you have asphalt shingles on the roof attic insulation is required to validate the shingles warranty. 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.

Near ridge of the roof. Hot air exhaust vents located at the peak of the roof allow hot air to escape. 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. You can also contact your local municipality to check on building code in your area.

Feet of attic space divided 50 50 between the inlets and outlets. Intake vents located at the lowest part of the roof under the eaves allow cool air to enter the attic. Air flows in through the soffit vents and out through the roof vents. Most building codes require a ratio of 1 150 ventilation space to attic floor space.

For the best results place roof ventilation near the roof s peak and soffit vents in the eaves. 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. Find a diagram of common air leaks here. Passive venting design usually includes both soffit and roof vents to promote.

Gaps in the attic or between the lower floors and the attic will let heated or cooled air escape to the great unconditioned outdoors making any insulation you add essentially useless. Foot of ventilation for every 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. Attic ventilation serves two main functions.