1. Identify Your Flue Type

Start by looking at what extends from the top of the chimney. Many masonry chimneys have a square or rectangular clay or terra cotta flue tile extending above the chimney crown. Other chimneys may terminate with a round chimney liner or require a cap that attaches to a top plate.

Identifying the type and shape of your flue will help narrow down which chimney caps and mounting options are appropriate for your installation.

2. Measure Your Chimney Flue

Don't choose a chimney cap based on the approximate size of the chimney. Measure the flue where the cap will actually attach.

For a square or rectangular clay flue tile, measure the outside width and outside length of the tile. Compare those measurements with the sizing specifications listed on the chimney cap's product page.

3. Choose the Right Mounting Style

Not every single flue chimney cap attaches the same way. A traditional flue-mount chimney cap attaches directly to an exposed clay or terra cotta flue tile.

Other applications may require a top-plate-mounted chimney cap, particularly when the chimney terminates with a stainless steel liner or another configuration that does not provide a suitable exposed tile for mounting.

Check the mounting requirements and dimensions listed on the individual product page before ordering.

4. Consider What You Need the Chimney Cap to Do

For many chimneys, a standard stainless steel rain cap provides dependable protection against rain, snow, animals, leaves, and debris.

Some chimneys have additional performance concerns. If your chimney experiences wind-induced downdrafts, a standard rain cap and a cap specifically designed to address wind-related draft problems are not necessarily interchangeable.

Fireside Chimney Supply also carries specialized wind-resistant options, including Vacu-Stack chimney caps designed for applications where wind-induced downdrafts and smoking are a concern.

The goal is to choose a chimney cap based on both fit and application, rather than selecting one based on dimensions alone.