What is a ridge vent?

A ridge vent is an exhaust outlet that runs the full length of a roof's peak, allowing trapped heat and moisture to exit the attic space. Installed directly under the roof decking at the highest point, it works as part of a paired ventilation system: air enters through soffit vents in the lower eaves and rises naturally out through the ridge, driven by temperature differences between the attic and outside air.

Ridge vents matter because they prevent moisture buildup that can rot decking and framing, reduce attic temperatures that degrade shingles and insulation, and help extend roof life. In Ontario's humid climate with temperature swings across seasons, balanced ventilation stops ice damming in winter and manages summer heat that can push shingles and nails beyond their rated limits. A properly installed ridge vent also reduces reliance on powered fans and keeps ventilation passive and cost-effective.

The vent itself is typically a slotted or perforated metal strip covered with a ridge cap shingle or flashing to keep rain out while letting air through. Contractors must ensure it matches roof slope and material, aligns correctly with soffit vents, and does not get blocked by insulation. Improper installation or mismatch with intake vents defeats the purpose. If you are planning ventilation work, a roof inspection professional can assess your current setup and advise on the right approach for your home.