Roof Ventilation Theory

The building codes and building science for.

Roof ventilation theory.

Vent the roof deck. Some other symptoms can help identify it as a vent blockage. Vents pipes can and do get blocked. However in pursuit of attic ventilation some people choose to install attic power ventilators.

An attic fan can be gable mounted or roof mounted. In a cold climate the primary purpose of ventilation is to maintain a cold roof temperature to avoid ice dams created by melting snow and to vent any moisture that moves. It s essential for reducing moisture and preventing excessive heat. Roof ventilation employs the third strategy.

A powered attic ventilator or attic fan is a ventilation fan which regulates the heat level of a building s attic by exhausting hot air. In some ways roof ventilation is as much as an art as it is a science and installing your own roof vents based on something you read online is like trying to diagnose a skin rash using webmd. This most commonly happens when debris or ice blocks the opening of the main vent stack on the roof but it can also happen in branch vents. Finding a trusted and experienced roofer who has worked in your region for his or her entire career is a better for your particular roof than any.

Effective attic ventilation systems reduce damaging heat and moisture in your attic promote energy efficiency by helping to reduce the load on your air conditioner in the summer and also reduce the risk of ice dam formation on your roof. A thermostat is used to automatically turn the fan off and on while sometimes a manual switch is used. Slits in the product allow for. A drip edge vent is made of a corrosive resistant material that sticks out about three inches back from the roof edge and then bends downward over them.

Vent roofs with steeples towers or cupolas can be found in different buildings from barns to cathedrals. The assumption is made that it is nearly impossible to control moisture entry into a roof assembly so removing it serves to prevent moisture accumulation. In theory these are excellent tools for circulating air in the attic and keeping the attic temperature low. Drip edge vents are a two in one installation that promote water shedding at the eaves and rakes of a roof while also allowing for ventilation into the attic.

In recent years building scientist have been conducting test and re thinking the accepted theory on roof ventilation. The intent of roof venting varies depending on climate but it is the same if you re venting the entire attic or if you re venting only the roof deck. If the attic space is going to be conditioned either for living or mechanical purposes or if a home design calls for a vaulted ceiling provision r806 3 in the international residential code calls for the roof deck above the space to be vented continuously from the eave to the ridge. Additional vents are required to draw in fresh air as the hot air is exhausted.

See the benefits of attic ventilation a new roof is more than just shingles.