Preparing Your Chimney for Winter

1. Hire a Chimney Sweep. Find a quality chimney sweep to clean your chimney. Chimneys that have not been cleaned in some time may have creosote build-up – a black or brown resident that can be crusty and flaky; tar-like and sticky; or shiny and hardened. All forms of creosote are highly combustible.

2. Inspect Chimney Liner for Damage. While your chimney sweep is working, ask him or her to check your liner for any damage. Cracks in the liner may lead to high temperatures reaching materials in walls and attics that are flammable or combustible.

3. Install a Chimney Cap. The possibility of flying debris finding its way into your chimney is greatly reduced if you have a chimney cap. Likewise, a cap with a wire mesh serves to stop any sparks or embers from causing rooftop fires. Chimney caps also help to prevent moisture and animals from getting inside your chimney system and causing unwanted damage.

4. Clear Overhanging Tree Limbs. Overhanging tree limbs present a potential fire hazard that can cause disastrous results if an ember makes its way up the flue. Tree limbs can potentially damage the chimney cap and can also restrict the draft of the chimney.

5. Clear Out the Ashes. Depending on how often you use your fireplace or stove, this is something that should be done relatively often. Whenever ash is more than an inch deep, it is a good idea to clean it. Before cleaning, be sure the ash is completely cold as coals can remain hot for extended periods of time in the ash.

6. Inspect Chimney Masonry for Cracks and Damage. The mortar used to construct your chimney will not last forever. If not properly maintained, the mortar may crack and flake. When this occurs, moisture can get into the chimney system. Over time, freezing and thawing cycles can lead to greater damage.

7. Inspect Chimney Flashing. For many, winter brings ice and snow to rooftops. Before that happens, we suggest inspecting the flashing around your chimney. The metal flashing is not as durable as the chimney itself. And invasive water may lead to damage to your roof and to the chimney itself.

8. Consider Installing a Cricket on your roof. If your local building codes do not require a cricket, depending on where your chimney is, installing one may be advantageous. A cricket (or saddle) is a ridge structure designed to divert water on a roof around the high side of a chimney. This functions to push water and moisture away from your chimney.

References:
https://www.csia.org/chimneyfires.html
https://en.wikipedia.org/wiki/Cricket_(roofing)
https://www.bobvila.com/slideshow/10-steps-to-readying-your-fireplace-for-winter-48090#bv-us