Exhaust vents are located near the top of the roof. Intake vents are usually located in the eaves or soffits. Most building codes require 1 sq. ft. of venting (technically, "net free vent area ...

Most shingle manufacturers void their warranties if roof venting standards aren’t met. Building codes generally require 1 sq. ft. of vent area for every 300 sq. ft. of attic floor. That assumes ...