Roof Ventilation – What Contractors need to know
Updated: Mar 24
Proper attic ventilation is a necessary part of every home and is utilized in every season.
A properly balanced ventilation system:
prevents heat buildup in the summer and moisture buildup in the winter
helps reduce energy consumption year-round
extends the life of the shingles and other roofing materials
prevents ice damming by equalizing the roof temperature
is required by the shingle manufacturer for a warranty to be valid
How do you know if the attic/roof is properly ventilated?
Check the balance of intake and exhaust vents. A properly ventilated attic/roof will have a balanced system of intake vents (i.e. soffit vents) and exhaust vents (i.e. ridge vents). The intake vents should be low at the roof’s edge while the exhaust vents should be high on the roof.
Check to make sure exhaust vents on the roof are not mixed together. Mixed exhaust vents will “short-circuit” the ventilation system and leave the lower portion of the attic unventilated. Exhaust vents were not meant to be intake vents – if the wind is coming in through an exhaust vent, so will rain, snow and debris!
Check the attic for moisture. Signs of moisture damage in the attic are a good indication the attic is not properly ventilated would be found in the attic. Look for mold stains on wood or rust on nails.
Check the intake vents for obstructions. If you cannot access the attic you can still check the intake vents for obstructions like wet compacted insulation, leaves or dirt.
Check the shingles. Curling or cracking shingles is another indication the roof is not ventilated properly.
Who pays for proper ventilation?
Insurance Carrier: Most insurance policies have building code coverage. If the homeowner has this coverage, typically the carrier will cover the cost of proper ventilation.
Homeowner: If the homeowner does not have code coverage, you will need to present the issue to the homeowner to decide how to move forward.
Did you know there are at least 2 apps available to assist with proper ventilation?
1) Vent Selector by Lomanco: http://www.lomanco.com/vent-resources/vent-calculator
2) Air Vent by Air Vent Inc.: http://www.airvent.com/index.php/ventilation-resources/attic-ventilation-calculator
The apps will calculate roof pitch and with minimal information from you, will give options as to the type of vent you want. They are user-friendly and will quickly give you the information you need to present ventilation to your homeowner.
You should download one or both of these apps from the Apple or Google Play stores before going on another inspection!
Impress your next client by showing them you have the knowledge to not only replace their roof but to help provide them with the benefits of proper attic ventilation!