Chimney cap

Animals that typically enter through chimneys include:

  • Raccoons: People will hear chirping sounds from the fireplace in spring. This often is due to a raccoon rearing her young above the damper.
  • Birds: Ducks, owls, pigeons, starlings, and chimney swifts find their way into chimneys. Under normal circumstances, only chimney swifts can exit a chimney.

A properly installed chimney cap will help prevent wildlife from entering through a chimney.

Capping a Chimney

This will save more than the life of the chimney. Contrary to public belief, only raccoons, chimney swifts, and bats can escape from a chimney flue. This means that chimneys are a death trap for all other animals. Countless starlings, pigeons, gray squirrels, and other wildlife die an agonizing death from falling into chimneys. Protect wildlife by capping your chimney.

In addition to saving wildlife, capping a chimney will protect the crown, the concrete portion around the flue of the chimney, from rain damage. A proper cap can add years to the chimney by deflecting the damaging rain that cracks the crown. Proper capping still allows dangerous gases to escape.

Items to Remember

Examples of commercial chimney caps with legs. Photo by Lynn Braband.
Examples of commercial chimney caps with legs. Photo by Lynn Braband.
  1. Cap all chimney flues with commercial stainless steel caps. Galvanized steel caps, popular years ago, break down due to rust.
  2.  Do not cover the chimney flue with hardware cloth. Not only does hardware cloth rust, it runs the risk of catching snow. This could block the escape of gases such as carbon monoxide, forcing them back into the house. This is especially true for chimneys that service gas furnaces. Gas furnaces produce a great deal of water vapor, which could freeze on the mesh. To learn more, obtain a copy of the National Fire Protection Association’s NFPA 211 Chimneys, Fireplaces, Vents and Solid Fuel-Burning Appliances 2019 edition and look at chapters 1-11.
  3. Measure the chimney flue. The flue is the orange tile that sticks out of the chimney at the external sides. Your flue needs to rise at least 1 inch above the surrounding chimney crown for these caps to be installed. If you don’t have a flue lip that is 1 inch high, you will need to purchase  a cap with legs. These hold the cap in place by inserting the legs into the chimney. The sizing of the cap does not have to be exact. For example, if the external sides of your chimney flue are 8.5″ x 8.5″, order a 9″x 9″ cap. The 3 standard-size chimney caps 9 x 9, 9 x 13, and 13 x 13.  
    If you have 2 flues side-by-side that are closer than 6 inches apart, install a multi-flue cap. A multi-flue cap allows protection of both flues with one unit. To measure for this type of cap, make sure that the crown is secure. You’ll need both the width and length measurements.