Rafter Baffles for Full-Vent Channel
Several articles on this or other sites advocate a 2″ deep rafter baffle for a “Full vent channel” However, soffit vent such as Hardie have 5 sq in/lf of venting. Assuming a 14.5″ wide rafter bay receives the venting from 16″ linear inches/ 1.33 lf of soffit, at 5 sq in/lf, 6.65 sq inches of venting goes to the 14.5″ wide bay. This requires less than a 0.5″ gap along the 14.5 ” to transfer all the air from the soffit vent up through the baffle. SO – would a 2″ deep baffle even matter? Seems like a big box store +/-1″ baffle would be good enough to transmit all the air the soffit can take up. Am I thinking about this correctly?
GBA Detail Library
A collection of one thousand construction details organized by climate and house part