Roof Ventilation Design

Attic ventilation works on the principle that heated air naturally rises primarily utilizing two types of vents.

Roof ventilation design.

The early to mid 20th century saw the development of this concept. For all roof designs however the most important feature of a roof ventilation system is adequate and balanced airflow. Advantages of proper roofing ventilation. An important part of a healthy home and a complete roofing system is roof vents.

The term refers to a system which allows air to flow through the intake and exhaust. 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. The model building codes allow both vented and unvented roof assemblies. Ventilation is important for all parts of your house and the roof is no exception.

Roof ventilation is not a new process by any means. 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. Roof ventilation helps to keep the attic dry and cool but it s also important to maintaining a healthy environment. Vent roofs with steeples towers or cupolas can be found in different buildings from barns to cathedrals.

In short an adequate and balanced ventilation system is one that allows an equal amount of air to enter and exit the attic area. Roof system ventilation is required by the model building codes such as international residential code irc which includes irc r806 roof ventilation that requires ventilation for attics and cathedral ceilings and icc r905 1 requirements for roof coverings that requires builders to follow the manufacturer s installation instruction. Normal household activities such as doing laundry running the dishwasher and taking showers generate warm moist air which rises from the living space and into the attic. Roof ventilation in a cold climate vents moisture and ensures a cold roof temperature to avoid ice dams.

The building codes and building science for natural roof ventilation however only appeared in the 1940s. Intake vents located at the lowest part of the roof under the eaves allow cool. What exactly does that mean. Attics or roofs can be designed and constructed to be either vented or unvented in any hygro thermal zone map 1.

Enter square footage calculate or enter the square footage of the attic or area to be vented.