Do You Need a Chimney Cap?

A stainless steel chimney cap installed on a faux chimney against a white background

A wood burning fireplace is a welcome feature for many homeowners. The warmth, the crackle of the fire, the dancing light — it’s an experience like no other.

At the top of that fireplace is a flue — the pipe made from clay tile that leads from the firebox to the top of the chimney, allowing smoke and other gasses to escape your home.

The problem with flue tile is that it’s wide open. It provides a direct line from the outside world to your firebox, an uninterrupted path that’s just begging for damage to be done to it.

And that’s where chimney caps come in.

At HY-C, we’ve been making chimney caps for over 75 years. In this guide, we want to help you determine whether or not you need a chimney cap on your home and, if you do, how to find the right one.

By the time you’re finished here, you’ll know whether you need a chimney cap on your flue (or if you need to replace your existing cap). You’ll also know how much a new cap will set you back, how to measure for your next chimney cap, and even how to install one.

What Is a Chimney Cap?

A chimney cap (also called a chimney cover or a rain cap) is a metal hood that attaches to the top of your chimney flue. Chimney caps are made up of three key components:

  1. The band at the bottom that accommodates bolts to secure the cap in place
  2. The metal mesh that allows smoke and other gasses to escape the flue
  3. The hood on the top of the cap that covers the open flue

Chimney caps come in all kinds of shapes and sizes, and they’re made from a variety of materials based on your needs and budget.

What Does a Chimney Cap Do?

Chimney caps serve two main functions:

  1. Keeping weather out of your chimney
  2. Keeping wildlife out of your chimney

Chimney Caps and Weather

HY-C founder Al Hisey sitting on a multi-flue chimney cap mock-up with a bucket between the flue tiles all in a backyard

One of our earliest slogans at the HY-C company was, “An open chimney is like an open bucket.” As rain falls over an open chimney flue, it pools in the firebox. This can cause mold and mildew buildup in the fireplace, or rainwater to flow from the firebox into the rest of your home.

During cold months, precipitation will cling to the walls of the flue or chimney brick and freeze. Frozen water expands, causing cracks in the walls of the flue. These cracks are dangerous, as they don’t allow flue gasses to vent properly.

Simply put, a chimney cap helps to solve all these issues.

Chimney Caps and Wildlife

An old HY-C chimney guard with cartoon animal cutouts of a squirrel holding a sign that says "Locked out - violation of right - denied re-entry" and birds holding a sign that says "Unfair - organized home builders of America"

An open chimney isn’t just a target for weather. Curious critters of all kinds will come across an uncovered flue, viewing it as a perfect place to set up their newest home.

That’s how “chimney swifts” got their name. These birds have the unique ability of taking off vertically. As a result, chimneys are perfect homes for them. They can come and go easily, all while enjoying complete protection from the outside world.

Raccoons are another common chimney invader. They’re one of the few nuisance wildlife animals that are able to scale slippery chimney flue tile without issue. They’ve been known to make nests on a chimney’s smoke shelf, even having and raising entire litters inside chimneys.

The best way to prevent these wildlife invasions is to cut them off at the source with a chimney cap.

How Much Does a Chimney Cap Cost?

The cost of a chimney cap varies based on its size and material. A basic, bare-bones cap will cost between $50 and $150. The bigger the cap, the more expensive it will be (because it uses more material than a smaller cap). But your choice of material can increase the price.

Chimney caps are typically made of one of three types of metal:

  • Galvanized steel
  • Stainless steel
  • Copper

Galvanized steel is the most economical chimney cap material.

A stainless steel chimney cap, on the other hand, offers a bit more in terms of durability and corrosion resistance (though they are more expensive as a result).

Finally, copper chimney caps are by far the most expensive. They offer comparable protection to their steel counterparts. But, as copper is a premium material, copper caps demand a premium price tag.

How Much Does a Chimney Cap Cost CTA

What Size Chimney Caps Are There?

There are quite literally dozens of chimney cap sizes available, and we cover them in-depth in our chimney cap size guide. And while there are too many sizes to list here, we can cover a few of the most common sizes.

Chimney caps fall into one of two categories:

  • Single-flue chimney caps
  • Multi-flue chimney caps

Multi-flue chimney caps vary widely in size, while single-flue caps are a bit more straightforward. Here’s a look at the five most common single-flue chimney cap sizes we sell at HY-C:

  • 13” x 13”
  • 9” x 9”
  • 9” x 13”
  • 13” x 18”
  • 9” x 19”

Between round chimney caps, square caps, rectangular caps, and multi-flue caps, there’s so much more to explore on the topic of chimney cap sizes. We’d encourage you to check our chimney cap size guide for more information.

What size chimney cap do you need CTA

How Do You Install a Chimney Cap?

Half the battle of installing a chimney cap is finding the right size. After you’ve done that, the installation is pretty self-explanatory. The mesh of the chimney cap hangs over the band, allowing you to set the cap right on the flue tile.

A close-up of the corner of a stainless steel bolt-on chimney cap being installed on a chimney flue tile

From there, the rest is easy. Just tighten the bolts on all four corners of the chimney cap onto the flue tile. Make sure the bolts aren’t so tight that they’ll crack the flue, but not so loose that a medium-strength wind could sweep the cap right off your chimney.

While simple bolts are the most common chimney cap installation method, there are, admittedly, several ways to install a chimney cap based on how the cap itself is built. Our chimney cap installation guide covers seven different installation methods and should help cover your bases.

Chimney Cap Installation Guide CTA

Do You Need a Chimney Cap?

There’s much more to the world of chimney caps than you may have imagined. From cost and materials to sizes and installation methods, these seemingly straightforward covers have more to offer than first meets the eye.

But back to the original question: Do you need a chimney cap?

A better way to think about that question is like this: Do you need to use an umbrella when it rains?

Of course, the answer is “no” — you can survive the rain just fine without an umbrella. But would it be much more comfortable, easy, and convenient to use an umbrella? Absolutely.

The same goes for chimney caps.

They aren’t necessary. You’re not required to have or use one. But installing one will make your life so much easier. It will keep weather and wildlife out of your home while allowing smoke and flue gasses to escape your fireplace properly.

For a simple investment of just $50 to $150, you can save yourself thousands of dollars in repairs or pest control bills down the road.

So take a look at your flue pipe this evening and, if it’s uncovered, consider adding a chimney cap to it. You’ll thank yourself next time it rains, or when the raccoons come knocking.

5 Signs it's Time for a Chimney Cap Replacement CTA