Roof Ventilation Design

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

Roof ventilation design. Roof ventilation is not a new process by any means. As a homeowner it is important that you review the soffit areas of the home for soffit vents. Attics or roofs can be designed and constructed to be either vented or unvented in any hygro thermal zone map 1. Vent roofs with steeples towers or cupolas can be found in different buildings from barns to cathedrals.

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 early to mid 20th century saw the development of this concept. 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. Ventilation is important for all parts of your house and the roof is no exception.

Advantages of proper roofing ventilation. The term refers to a system which allows air to flow through the intake and exhaust. An important part of installing any system of ventilation into your roof system is to make sure that there is a point of entry and a point of exit for airflow. An important part of a healthy home and a complete roofing system is roof vents.

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. 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. Enter square footage calculate or enter the square footage of the attic or area to be vented. The model building codes allow both vented and unvented roof assemblies.

The building codes and building science for natural roof ventilation however only appeared in the 1940s. Roof ventilation in a cold climate vents moisture and ensures a cold roof temperature to avoid ice dams. The installation of roof vents is a crucial part of roof design because it allows for proper attic ventilation which may help prevent condensation and early aging of your roofing materials. Roof ventilation helps to keep the attic dry and cool but it s also important to maintaining a healthy environment.

For all roof designs however the most important feature of a roof ventilation system is adequate and balanced airflow.