What is a ridge vent on a house, and how do I know if mine has one?
Short answer. On a house, the ridge vent is the slightly raised, shingle-covered strip along the very top of the roof that lets attic air out. To know if yours has one, look from outside for a thicker ridge line with the vent's edge showing at the gable ends, and look from the attic for a line of daylight along the peak.
Check from outside
- View the roof from across the street at a low angle. A vented ridge looks thicker and sits about an inch off the roof.
- Look at each gable end for the edge of the vent material under the last cap shingle.
- Rows of box vents or turbines near the top usually mean no ridge vent, or a mixed system that needs attention.
Check from inside
- On a sunny day, look up at the peak from the attic. A working ridge vent shows a slot of light along the top of the deck.
- If the peak is solid wood, either there is no ridge vent, or a vent was installed without the slot being cut.
If you have one
- Make sure the soffit vents are open and not buried in insulation.
- Close off gable vents and retire any power fan that competes with it.
- After strong storms, look for lifted cap shingles along the ridge.
If you do not
Your attic may rely on other exhaust, which is fine if it is sized correctly. A roof replacement is the natural time to consider switching. Read roof ventilation basics and what to expect from a roof inspection.