What is the easiest and fastest way to fix a chimney leak?
Find the source quickly
A hose test is the fastest way to stop guessing. On a dry day, one person runs a garden hose gently over one area at a time, starting low and working up: the downhill face, each side, the uphill side, then the crown. A helper in the attic watches for water. When it shows, you have found the leak. Work from the bottom up so water from higher areas does not confuse the result.
Quick fixes that hold
- Install a cap. If water shows in the firebox or at the flue, a properly sized cap stops rain entry right away.
- Reset counterflashing. If the top metal has pulled out of its joint, it can be reset into a clean, sealed reglet in the mortar.
- Seal crown cracks. Hairline cracks in an otherwise sound crown can be sealed with a crown sealer made for the purpose.
- Breathable water repellent. On porous brick, a masonry repellent cuts absorption quickly. It is not a fix for flashing.
Quick fixes that fail
- Caulk or roof cement around the base, which cracks in Georgia heat and traps water.
- Spray coatings over flashing and shingles.
- Painting or film sealers on brick, which trap moisture.
When there is no shortcut
Rusted, missing or improperly installed step flashing has to be replaced by removing the shingles around the chimney and weaving new pieces in. A wide chimney leaking on the uphill side needs a cricket. Patching these only delays the real repair while the decking rots.
Stay safe
Chimney work often means standing on a steep slope high off the ground. If you are not comfortable on a roof, leave it to a pro.