Roof ventilation
A roof needs to breathe. Air comes in low at the soffit and leaves high at the ridge — when that stops working, the damage happens out of sight.
Why ventilation is a roofing problem
Warm, damp air from the house rises into the attic. If it cannot get out, it condenses on the cold underside of the roof deck. Over a winter that means damp sheathing, wet insulation and, at the eaves, the melt-and-refreeze cycle that builds ice dams — all of it happening above the ceiling where nobody looks.
Intake and exhaust have to balance
Exhaust vents at the top of the roof can only pull air out if intake vents at the soffit let air in. Adding more roof vents to an attic with blocked or missing soffit intake does not fix the problem — it just pulls air from inside the house instead.
What poor ventilation looks like
- Frost or damp on the underside of the roof deck in winter
- Ice building up along the eaves
- Matted, damp insulation in the attic
- A roof that has worn out noticeably faster than it should have
What to send us
Tell us what you are seeing in the attic or at the eaves, and your address. Photos from inside the attic are genuinely useful here.
Related roofing services
Work that often goes with roof ventilation.
Soffit & fascia
The soffit is the underside of the roof overhang; the fascia is the board that closes off its edge. Together they finish the roof and let it breathe.
Soffit and fascia details
Re-roofing
Replacing a roof that has reached the end of its life — the old covering comes off, the deck is checked, and a new roof system goes on.
Re-roofing details
Asphalt shingles
The most common roof covering on homes in this area — an asphalt shingle roof, installed over proper underlayment and flashing.
Asphalt shingle roofing detailsThinking about roof ventilation?
Send us the details and Georgian Bay Roofing will follow up with next steps.
Tell us what you need help with
Share a few details about your roof and the best way to reach you. We'll follow up to confirm what we can do.