Chimney Leak Checklist

Is your chimney leaking? Are you experiencing water marks on the ceiling or walls near your chimney? Is there water appearing in the firebox? Similarly, are you experiencing cracks on the exterior of the chimney which seem to keep getting bigger or are bricks actually flaking off from your chimney? Water is the common thread between all of these problems (for the most part) and following this checklist should help you to be able to arrest water infiltration or prevent further damage.

Chimney Cap
Installing a stainless steel chimney cap is inexpensive and generally maintenance free.

1. Do you have a chimney cap?

If water is able to fall freely down your chimney, installing a chimney cap will help you out. By preventing water from entering your firebox or dripping down the walls of the chimney’s flue, you will be able to lessen the amount of creosote that will build up and prevent damage inside the flue system from the water. Install a stainless steel chimney cap. These will not rust and resist deterioration over time. Rust stains from painted black chimney caps or other metals which are able to rust are a huge issue for homeowners.

Damaged Chimney Crown
This cracked chimney crown may allow water to enter the chimney.

2. Is  your chimney crown cracked or damaged?

If so, this may be another point of entry for water into your home. Call in a chimney professional for evaluation. If the crown can be repaired by resurfacing, this is a repair you can do yourself using a crown resurfacing product. If the chimney crown is severely damaged structurally, you will need to have it replaced. Whether you are replacing or resurfacing your crown, applying a water repellent over the entire crown will help to extend the life of the repair and prevent damage from happening in the future.

3. Are there any cracks or missing mortar joints in the brick on the chimney?

Brick Damage


If your brick is damaged, water may be able to enter your home. If there are missing mortar joints or cracks in the brick itself, these are all points of entry for water. These cracks need to be sealed using a sealant so that there is a physical barrier between water and the crack. There are various types of sealants for repairing cracks in brick, but I recommend a silicone sealant. If you have missing mortar joints, these will need to be put back in through a process called tuckpointing. If you have very extensive damage to your chimney, you may want to have a chimney professional come out to evaluate your chimney. If the damage is bad enough, the chimney may need to be partially or completely rebuilt.

4. Is your flashing rusted or pulling apart from the home?

Flashing Problems


If your flashing is not in good condition, this is another point of entry for water that homeowners often overlook. Rusted flashing must be replaced, either by a professional or by yourself if you have the skills to do so. Some flashing can be repaired using a flashing repair system, but the most lasting repair is going to be replacing it. A flashing repair system is good for when the flashing seems to be intact and has no visible damage. These systems seal the flashing, barring water from entering.

Clay Lamb

Clay Lamb is a Cincinnati Chimney Sweep contractor and the executive producer of the YouTube channel, podcast, and blog Ask the Chimney Sweep. He is also an award-winning educator and public speaker in the chimney and fireplace industry.….Educational Videos….American Chimney Cincinnati, OH We are a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for us to earn fees by linking to and affiliated sites.

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