Attic Ventilation Requirements California

Roof ceiling construction requirements are listed in california residential code chapter 8.

Attic ventilation requirements california.

In climate zones 14 and 16 a class i or ii vapor retarder is installed on the warm in winter side of the ceiling. Not less than 40 percent and not more than 50. This handout is intended to provide the information regarding proper roof ventilation and insulation clearance. Federal housing authority recommends a minimum of at least 1 square foot of attic ventilation evenly split between intake and exhaust for every 300 square feet of attic floor space.

Vents are vulnerable to wildfires when embers and flames enter into the enclosed attic or crawl spaces and ignite combustible materials in those areas. A ridge vent and through roof vents can be seen on the roof of the building shown here. 1203 3 the uniform building code requires enclosed attic spaces enclosed rafter spaces and under floor areas to be ventilated by not less than 1 square foot for each 150 square feet of attic under floor area. Proper attic ventilation consists of a balance between air intake at your eaves soffits or fascias and air exhaust at or near your roof ridge.

The minimum net free ventilation area shall be 1 300 of the vented space provided one or more of the following conditions are met. 1203 2 under floor ventilation. California title 24 part 6 references ashrae standard 62 2 2007 as california s state ventilation code with one exception. These requirements cover the design and construction of roof ceiling systems including roof framing roof drainage roof sheathing ceiling finishes roof ventilation and attic access.

Ventilation guide 2007 california building code attic ventilation. 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. If your attic is enclosed california s building code states it should have cross ventilation. The minimum net free ventilating area shall be 1 150 of the area of the vented space.

Operable windows are excluded from the options for meeting whole building ventilation requirements.