Attic ventilation works on the principle that heated air naturally rises primarily utilizing two types of vents.
Design attic ventilation.
Also see insulation air heat leaks.
Get started indoor air quality iaq poor indoor air quality can have a negative effect on your home.
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.
Most effective ventilation uses a ridge and soffit continuous ventilation system but even these designs can vary from roof to roof.
Traditional design better attic venting is achieved with continuous soffit intake and ridge outlet venting.
The model building codes allow both vented and unvented roof assemblies.
Attics or roofs can be designed and constructed to be either vented or unvented in any hygro thermal zone map 1.
Hot air exhaust vents located at the peak of the roof allow hot air to escape.
After these are installed close off the gable end vents for best venting performance as discussed above.
Soffit vents may leave air trapped at the top of your attic.
Ventilation of attic spaces is required by most building codes as well as by roofing material manufacturers and the national roofing contractors association nrca.
Enter square footage calculate or enter the square footage of the attic or area to be vented.
Attic ventilation estimating tool.
Grab a flashlight and inspect your attic during the winter.
For the best results place roof ventilation near the roof s peak and soffit vents in the eaves.
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.
Replacing your bathroom fan range hood or even installing a new fan.
There are some styles of vaulted ceiling homes or flat roof homes that have ventilation spaces within the roof itself and no attic.
Intake vents located at the lowest part of the roof under the eaves allow cool air to enter the attic.
Add continuous soffit vents at the eaves.
If you see dampness or frost you need better roof ventilation and some attic vents.
These ventilation needs are calculated differently.
Most building codes require a ratio of 1 150 ventilation space to attic floor space.
Static roof line vents are effective for ventilation but generally aren t recommended due to issues with leaks.
You can also contact your local municipality to check on building code in your area.
Use this tool to estimate the ventilation needs for your attic and get a list of broan attic ventilation product that will meet your needs.
Air flows in through the soffit vents and out through the roof vents.
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.
