What this covers
Roof ventilation moves outside air through the attic: in at the soffit vents, out at the ridge or gable, carrying heat in summer and moisture in winter. The roofer calculates the attic's needs, installs or clears soffit intake, adds baffles so insulation does not block it, cuts the ridge for a continuous ridge vent or adds box or powered vents, and closes off mixed systems that short-circuit the airflow. Poor ventilation cooks shingles from below, breeds mold on the sheathing and feeds ice dams at the eaves. Careful work shows in balanced intake and exhaust, baffles at every bay, and a check of bath fan and dryer ducts that should exit outside rather than into the attic.
When to call
- Ice dams along the eaves every winter.
- An attic that is stifling in summer or shows frost and damp sheathing in winter.
- Shingles aging faster than they should, especially on the south side.
- Mold or dark staining on the underside of the roof deck.
What to expect
- AssessAttic size, existing vents, insulation and bypasses are measured and inspected.
- DesignIntake and exhaust are sized and balanced for the attic and roof shape.
- InstallSoffit vents, baffles and ridge or roof vents are installed and old vents closed where needed.
- CheckAirflow and the exhaust of fans and dryers are confirmed.
Get a certified company
Look up a certified company by ZIP code. Every company's license, insurance and trades are verified before it is listed, and placement is never paid.
Questions people ask
Why do intake and exhaust need to balance?
Exhaust without intake pulls conditioned air from the house through every gap. Intake without exhaust does little. The two work as a pair.
Is a powered attic fan a good idea?
Sometimes, but it can depressurize the attic and pull air from the house if intake is short. A continuous ridge vent with open soffits is the usual first choice.
Does ventilation stop ice dams?
It helps a great deal by keeping the roof deck cold, along with sealing attic bypasses and adding insulation. Ice barrier at the eaves handles what still melts.
Related: Soffit and fascia repair · Roof replacement · Ice dam leak repair · All roofing and gutters
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