Old Attic Pitched Roof Proper Ventilation

If there are asphalt shingles on your roof the attic must be ventilated to comply with the terms of the manufacturer s warranty.

Old attic pitched roof proper ventilation.

The ventilation amount and opening size requirements can be found in section 806 roof ventilation of chapter 8 roof ceiling construction. Whole house fans powered attic fans. The space above the top plate of exterior walls at the bottom of each rafter bay is especially important. In of vent opening per 150 sq.

Pitched roof ventilation is beneficial in all climate zones and in. These fans may be controlled by a switch or a thermostat which detects heat build up in the attic space and automatically exhausts the attic space. Roof ventilation is crucial to attics as it positively affects the home inside and out. If the slope of your roof is greater than 6 12 you will need more ventilation to reflect the extra volume of attic space.

Attic ventilation works on the principle that heated air naturally rises primarily utilizing two types of vents. Don t avoid ventilating your attic for fear you re letting cold air into the house. Then aim for about 1 sq. Pitched roof ventilation is achieved by creating air changes in the attic.

Your actual living space is sealed and insulated at the attic floor the attic is outside this envelope. The following are the requirements taken directly from the irc. The success of a vented attic or roof deck relies on its airtightness. Most effective ventilation uses a ridge and soffit continuous ventilation system but even these designs can vary from roof to roof.

Intake vents located at the lowest part of the roof under the eaves allow cool. Baffles placed in this area channel intake air into either the attic space or vent chutes and also prevent insulation from falling into the soffit and blocking airflow. The majority of the requirements related to attic ventilation have not changed much from the previous editions. If not measure the size yourself.

Removal of excess heat and moisture will help the life of the roof and the efficiency of the hvac systems within. Calculate 20 per cent more for 7 12 to 10 12 pitches and 30 per cent more for a pitch that is 11 12 or greater. The open area of a vent is sometimes listed on the roof air vent as nfva net free vent area.