Here’s a list of the 3 main reasons every chimney should have a cap:
  1. They are guaranteed to keep out animals – Birds, bats, squirrels, and raccoons can easily enter the top of an uncapped chimney. Animal nests cause chimneys to become blocked, which can allow smoke and CO to enter the living area. Animals can also die in chimneys or enter the living area, both are unpleasant experiences. Installing a chimney cap is often less expensive than removing an animal or a nest.
  2. They are guaranteed to keep out debris – Outside debris like branches, leaves, etc. can also block a chimney. This debris can also cause the fireplace damper to become difficult to operate.
  3. They help prevent water entry – Water will rust out your damper and any other metal components in a fireplace. Water will also rust out the connector pipes for your furnace, and potentially the furnace itself. Water also erodes the mortar joints between the flue tiles that line a masonry chimney, which leads to relining or other expensive repairs.

If your chimney does not have a cap, if your chimney cap is rusted out, or if you are unsure, here’s a link to the chimney cap page on my website.