Five Common Causes of Poor Attic Venting
Problem 1: Insulation often clogs the space between the rafters, blocking air from traveling to and from the soffit area. Solution: Install air chutes or clear them if they're clogged (Photo 1).
Problem 2: Aluminum or vinyl soffits (eaves) installed over plywood soffits that don't have venting holes. Solution: Cut holes in plywood soffits as needed.
Problem 3: Gaps to the attic around plumbing pipes, ducting and electrical boxes. Many experts consider plugging these holes to be more important than ventilation. Solution: See Photo 2.
Problem 4: Rectangular roof vents installed on one side of the roof only. Rectangular roof vents work best when the wind blows over the top of them, rather than into them. Solution: Install rectangular roof vents on both sides of the roof.
Problem 5: Kitchen and bath fans vented into the attic. Solution: Vent these fans through the roof or soffit.