Inadequate attic ventilation can reduce
the life of your roof up to 50 percent. In poorly ventilated homes
moisture forms condensation on the underside of the plywood sheeting of
the roof causing the plywood to expand, buckle and delaminate. Attic
ventilation will also allow hot air to escape during the heat of the
summer. When ventilation is not adequate most shingle manufacturers void
warranties if their shingles are installed over improperly standards or
the U.B.C. ( Uniform Building Codes) which calls for :
1. One square foot of ventilation for
every 300 square feet of attic space.
2. One half of the vent area should be
intake, and the other half should be exhaust.
