How often should roof vents be replaced?
Short answer. Most roof vents should be replaced every time the roof is replaced, because their flashing is woven into the shingles and ages with them. Between replacements, replace any vent that is cracked, rusted, dented by hail or leaking; rubber pipe boots are the part most likely to fail before the shingles do.
How each vent ages
- Box vents: metal ones dent in hail and can rust at the edges; plastic ones get brittle in sun and crack. Either way they usually outlast the roof only barely.
- Ridge vent: hidden under cap shingles, it is replaced with the caps at every reroof and rarely between.
- Turbines: bearings wear, heads wobble and squeal, and seized turbines stop venting. Replace when they stop spinning freely.
- Powered fans: motors and controls fail on their own timeline, separate from the roof.
- Pipe boots: the rubber collar cracks from sun and heat, often well before the shingles wear out.
- Exhaust caps: dampers stick, and plastic hoods crack.
Why replacement goes with the roof
A vent's flange tucks under the shingles above it and laps over the shingles below. When those shingles come off, the old vent's nail holes, bent flanges and aged sealant are not worth reusing. New vents also let the roofer correct the ventilation design rather than copy the old one.
After a storm
Dented metal vents and cracked plastic ones are among the clearest signs of hail. Adjusters look at soft metals like vents to judge hail size, so photograph them before anything is repaired. Check whether hail hit your area with the free hail history at North Georgia Hail Map.
Simple checks
Binoculars from the yard each spring and after big storms, and a flashlight look in the attic around each vent after heavy rain. See pipe boot leaks and Georgia hail season.