Roof Design Ventilation

In cold climates the primary purpose of attic ventilation is to maintain a cold roof temperature to avoid ice dams created by melting snow and to vent moisture that moves from the conditioned space to the attic.

Roof design ventilation.

Enter square footage calculate or enter the square footage of the attic or area to be vented. 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. Advantages of proper roofing ventilation.

An important part of a healthy home and a complete roofing system is roof vents. 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. 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. Roofs can be designed and constructed to be either vented or unvented in any hygro thermal zone.

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. In short an adequate and balanced ventilation system is one that allows an equal amount of air to enter and exit the attic area. The model building codes allow both vented and unvented roof assemblies. Cool air in hot air out attic ventilation works on the principle that heated air naturally rises primarily utilizing two types of vents.

For all roof designs however the most important feature of a roof ventilation system is adequate and balanced airflow. 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. The building codes and building science for natural roof ventilation however only appeared in the 1940s. What exactly does that mean.

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. As a homeowner it is important that you review the soffit areas of the home for soffit vents. Roof ventilation helps to keep the attic dry and cool but it s also important to maintaining a healthy environment.