How to Successfully Repair a Chimney Leak

Written by Doityourself Staff
on Sep 14, 2011

To ensure our content is always up-to-date with current information, best practices, and professional advice, articles are routinely reviewed by industry experts with years of hands-on experience.

Reviewed by
H.R. Helm
on Feb 03, 2023

2-6 hours
•
Intermediate
•
0-200

Good Hammer or roofing hammer

Caulk gun and silicone caulk

Crowbar

Plastic trowel

Cold tar

Extension ladder

Good Hammer or roofing hammer

Caulk gun and silicone caulk

Crowbar

Plastic trowel

Cold tar

Extension ladder

A chimney leak can be painfully annoying for any homeowner. A chimney leak is usually caused by a poor job of sealing or not roofing around the chimney properly. Weather and wear can also cause issues. For the do-it-yourself type of person these repairs can be very easy.

The Process of Repairing a Chimney Leak

Use these basic steps to successfully repair your leak issue.

Step 1 - Examination

Examine the chimney for cracks around the base, on the sides, and behind it.

Step 2 - Find the Flashing

Re-examine the sides of the chimney and look for six to eight inch long pieces of metal. This metal is called chimney flashing. When the chimney was built they blended the metal into one of the first row of bricks. In many climates this causes the mortar to expand and contract causing a chimney leak.

Step 3 - Investigate Cracks

Look for cracks between the metal and row of bricks on top of it.

Step 4 - Caulk it up

Place a medium sized amount of caulk all the way on the sides and back of the chimney except for the front.

Step 5 - Check One More Location

Also check where the roof shingles meet the metal flashing for another chimney leak that may exist.