Ridge Vents
The amount of venting depends upon the size of the roof, roof design/structure, (attic present or not, etc.) as well as local climatic conditions. Check with your local building official for requirements in your area. One rule of thumb for venting the attic area is 1 square foot per 150 square feet of floor area. One half of this (1/2 square foot per 75 square feet of floor area) amount should be in the soffit or eave and one half (75 square feet) in the roof system. In the case of a balanced system 1 square foot per 300 square feet of floor area may be adequate ventilation. Check with your local building official.

Low Slope (6:12 or less)
The CSSB recommends the installation of ridge vents that allow for installation of pre-manufactured ridge applied over the vent material. There are many manufacturers of this design.

Steep Slope (8:12 or greater)
On steep slope roofs, the correct ridge ventilation products can actually facilitate the ease of installation of Certi-label™ ridge units. Always follow the manufacturer’s installation instructions. The predominant ridge material manufactured today is for a low slope roof. However, by using a ridge vent that is malleable and at least 8 1/2" wide, the material can be installed across the minimum 3" of air space at the ridge to create a shallowing of the slope at the ridge. Care must be taken to caulk the ridge ventilation material to the Certi-label™ shakes or shingles. Proper nailing of the ridge units will create a serviceable application.

Severe Climate Areas
In all wind driven snow areas, the proper ridge ventilation product should have a screening effect to prevent snow infiltration (not louvered or baffled).