If your chimney flue vents directly into the open air at the top, installing a chimney cap is one of the smartest investments you can make. A chimney cap covers the flue while leaving enough space for smoke and gases to escape freely. It keeps rain and snow off the masonry crown, blocks debris and small animals, and can even help improve draft. The type you should choose depends on your chimney's configuration, the functions you need it to perform, and your personal style preferences.
Chimney Cap Materials
Chimney caps are made from several different metals, including copper, aluminum, black-painted steel, and stainless steel. The top cover is wide enough to keep precipitation off the top of the chimney, while the open sides are typically enclosed with screen or mesh. This mesh serves double duty — acting as a spark arrestor while also keeping out leaves, squirrels, birds, bats, and other small animals. Most caps are made of corrosion-resistant metals or finished with protective coatings, so you can pick the material and color that best matches the exterior of your home.
Base Shapes to Match Your Flue
Chimney caps come in different base shapes to fit different flue types:
- Round bases fit cylindrical metal chimney liners.
- Rectangular bases fit standard rectangular clay tile flue liners and slide over the outside of the top tile.
- Multi-flue caps cover multiple flue openings with a single unit, or you can install individual caps for each flue.
Matching the base to your flue type is essential for a proper, secure fit.
Basic vs. Specialty Chimney Caps
A basic chimney cap protects the chimney from precipitation and keeps debris and animals out. In some cases, the geometry of a basic cap can even improve your chimney's draft — though soot buildup on the mesh can eventually restrict airflow if it isn't cleaned periodically.
For homes in windy locations, specialty chimney caps are designed to create a vacuum inside the flue when it's windy outside. These caps help solve downdraft problems that basic caps can't address.
Top-Sealing Damper Chimney Caps
If you want to boost your home's energy efficiency, a chimney cap with a built-in top-sealing damper is one of the best upgrades you can make. Old metal fireplace dampers often don't seal well even when fully closed, allowing cold air to leak into your home when the fireplace isn't in use. A top-sealing damper cap features a cable that runs down through the flue to a lever inside your fireplace, letting you open and close the damper from indoors. Once closed, you'll immediately notice fewer cold drafts in the room.
Ready-Made or Custom
The wide variety of chimney caps on the market means most homeowners can find exactly what they need by shopping online or at their local chimney supply store. And if you have an unusual flue configuration or a specific look in mind, most chimney cap manufacturers can build a custom cap to your exact specifications at a reasonable price.