Design Attic Ventilation

Also see insulation air heat leaks.

Design attic ventilation.

Ventilation of attic spaces is required by most building codes as well as by roofing material manufacturers and the national roofing contractors association nrca. You can also contact your local municipality to check on building code in your area. The amount of space you devote to intake must be equal to the amount you allow for exhaust and these must be calculated according to the size of your attic and slope of your roof. The choice of venting or not venting is a design and construction choice not a requirement determined by the physics or by the building code.

Soffit vents may leave air trapped at the top of your attic. Grab a flashlight and inspect your attic during the winter. Replacing your bathroom fan range hood or even installing a new fan. After these are installed close off the gable end vents for best venting performance as discussed above.

Hot air exhaust vents located at the peak of the roof allow hot air to escape. The first is the air entering through the circular soffit vents that incorporate a wire mesh referred to as bird blocks moreover there are other popular soffit vent styles including perforated lots or panels below the soffit. If you see dampness or frost you need better roof ventilation and some attic vents. Get started indoor air quality iaq poor indoor air quality can have a negative effect on your home.

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. The key to proper ventilation of your roof and attic is balance. Attic ventilation estimating tool. Traditional design better attic venting is achieved with continuous soffit intake and ridge outlet venting.

For the best results place roof ventilation near the roof s peak and soffit vents in the eaves. Most effective ventilation uses a ridge and soffit continuous ventilation system but even these designs can vary from roof to roof. Air flows in through the soffit vents and out through the roof vents. The model building codes allow both vented and unvented roof assemblies.

Most building codes require a ratio of 1 150 ventilation space to attic floor space. Enter square footage calculate or enter the square footage of the attic or area to be vented. Add continuous soffit vents at the eaves. Attics or roofs can be designed and constructed to be either vented or unvented in any hygro thermal zone map 1.

Attic ventilation works on the principle that heated air naturally rises primarily utilizing two types of vents. There are some styles of vaulted ceiling homes or flat roof homes that have ventilation spaces within the roof itself and no attic. These ventilation needs are calculated differently. Intake vents located at the lowest part of the roof under the eaves allow cool air to enter the attic.