Many of our customers ask us why we need to look in to the attic in order to provide a quote? What does attic ventilation have to do with replacing or repairing my roof?
To answer this question, we need to understand what the purpose of attic ventilation is? Most homeowners and even some builders or contractors, believe the purpose of attic ventilation is to remove heat that builds up in the summer. This is true, but if you understand the principles of attic ventilation, you know an effective ventilation system provides year-round benefits and will actually help your roofing system last longer. There are two important principles to remember when installing attic ventilation;
- Ventilation is a balanced system of intake and exhaust.
- Air follows the path of least resistance.
Air should enter the attic at the lowest point, move up through the attic and exit at the ridge.
More than one type of exhaust system should never be installed -- the stronger exhaust vent will pull from the other one. When that happens, one of the vents is functioning as an intake vent and one as an exhaust vent, short-circuiting the ventilation system. Short-circuiting the ventilation system will leave large areas of the attic left un-ventilated because air circulates only at the top of the attic. If the secondary exhaust vent becomes an intake vent, it is prone to weather infiltration because exhaust vents are not designed to pull air into the attic. To get the most exhaust out of the attic, the intake area should be equal to or exceed the exhaust area. Many ventilation engineers recommend installing additional intake to maximize airflow.
At Precision Roofing Services, our roofing specialists may ask to look up in to your attic to inspect your ventilation system, particularly if you are experiencing water stains, bubbling or other signs of leakage. They will also check for signs of moisture damage such as mold stains on the wood, compacted insulation from moisture droplets and rust on nails.
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