Chimney

Rocky Raccoon

How to Keep Wildlife out of Your Chimney

Raccoons, squirrels, birds, bats — at some point or another, you may encounter any one of these critters in your chimney. Their presence can disturb your living space, cause costly damage to your chimney or fireplace, and at worst, curious or frightened wildlife may find its way into the rest of your home.

HY-C’s HY-Guard exclusion products have been protecting homes from nuisance wildlife for decades, and our chimney caps have been on top of flues for over 75 years. In the category of keeping animals out of chimneys, there’s nothing we haven’t seen.

In this guide, we’ll outline how a chimney works, which animals get into them, and how they manage to sneak in. We’ll also explain how a good chimney cap can go a long way towards keeping critters out of your chimney to help you keep your chimney — and your home — protected.

Parts of a Chimney

It’s important to visualize the components that make up your chimney so you can see both where critters get in and where they set up camp. A traditional fireplace is made up of several components, including the firebox, a damper, a smoke shelf, a smoke chamber, the masonry, and a flue. A standard chimney typically looks something like this:

HY-C HY-GUARD EXCLUSION Chimney Diagram

The firebox is what you see when you look into a fireplace from inside your home. Lined with firebrick, it’s where you burn the wood in your fireplace. The damper is an adjustable steel or cast iron plate at the top of the firebox, and its job is to regulate airflow through the firebox, into the smoke chamber, and up through the chimney. Behind the damper sits the smoke shelf — a flat area at the base of the smoke chamber designed to prevent reverse airflow (i.e., backdrafts) into the firebox. The smoke shelf also helps to protect the firebox from water, debris, or wildlife that makes its way down the chimney.

Atop the smoke chamber, the flue is the exit from which smoke and hot gas escape the chimney. It’s supported by the masonry of the chimney and it extends upward through the building, through the roofline, and ends at some level above the shingles.

The flue is the most common entry point wildlife uses to get inside a chimney, either intentionally to create a nest or by accidentally falling in. Critters may also enter the actual chimney structure through flaws in the masonry, missing mortar joints, or other external damage. Smaller wildlife can get in through openings at the base of the chimney if the flashing is faulty. Decay and extensive weathering on older chimneys may offer still more points of entry for local fauna.

What Kind of Wildlife Gets into a Chimney?

Squirrel on fence

Raccoons are infamous for using the chimney as a maternal den site; a female raccoon can easily climb up and down the inside of a flue. Normally, a mother raccoon births her babies (called “kits”) on the smoke shelf of a fireplace, so that should be the first place you check if you hear critters in your chimney.

Squirrels, bats, and birds can also get into the flue. Unlike raccoons, squirrels can’t climb back up the slick flue tile, and bats and birds have trouble navigating the narrow smoke chamber. Chimney swifts are a notable exception, though. These aptly named birds can fly vertically and have no issues making their home in a chimney. Swifts are protected by the Migratory Bird Treaty Act of 1918 and require special permits for removal.

In some cases, small animals might be able to enter through the cracks and crevices in the masonry or flue tiles. These infestations — usually flying squirrels or bats — are sometimes hard to recognize, but typically easy to exclude with regular maintenance.

What Are the Signs of Wildlife in Your Chimney?

There are two sure signs of wildlife inside a chimney: noises and odors. Noises like scratching, clawing, or just general movement indicate that there may be an animal on top of the damper or the smoke shelf. If the damper was left open, the culprit will likely be staring you in the face from your firebox (or even running around your living room). Chirps or chittering are usually indicative of birds or raccoons.

Odor normally suggests raccoons as well, but most homeowners can pick up the scent of a long-term bird roost and the droppings that come with it. If the odor is particularly foul, the critter may not have survived its time in your chimney. In this case, your priority shifts from animal capture to carcass removal.

How to Inspect Your Chimney for Wildlife

Starting an inspection is easy enough; all you need is a flashlight to peek into the firebox to check for wildlife. Inspecting the smoke shelf is a little more difficult. Visual access to the shelf is difficult, so you’ll need both a light and a camera. From the roof, you can use a strong light source and look down the chimney flue for critters, or you can lower a camera down the flue and play the footage back later. It’s important to note that we do not recommend climbing onto your roof. Leave all roof-level inspections to a professional wildlife control operator.

As the flue is being inspected for wildlife and nesting material, be sure to inspect the chimney itself for any signs of damage, blockage, cracks, weathering, or creosote buildup. Repairing these problems will not only keep future wildlife from getting in, but will also ensure an efficient chimney that functions properly. To really keep wildlife out of your chimney, though, nothing beats a top-of-the-line chimney cap.

How a Chimney Cap Can Keep Wildlife out of Your Chimney

If you don’t have a chimney cap, getting one is an absolute necessity. First and foremost, they keep animals and debris from entering the chimney flue and creating blockages and fire hazards. They also prevent downdrafts and rainwater from getting into the chimney flue.

A chimney cap can also improve the chimney’s draft, helping it to vent smoke and gas more easily. Caps made from galvanized steel, stainless steel, or copper are popular choices because they are aesthetically pleasing, and because nuisance wildlife can’t gnaw through them or rip them off the flue.

It’s important to consider the mesh size of your chimney cap, too. ¾” mesh is common on most caps, but homes in some parts of Oregon and California require ⅝” mesh by law (to stop sparks from escaping and causing forest fires). Mesh size is a balancing act; the mesh needs to be small enough to prevent small animals from accessing the flue, but large enough to allow smoke and gas to escape to stop creosote from building up or ice from forming.

Keep Wildlife out of Your Chimney

The idea of an unwelcome animal making a home in your chimney is unsettling. By now, though, you understand how your chimney works, what kind of animals tend to get into it, how to check for those animals, and how to keep them from accessing your flue in the future.

The best thing to do now is to find the right chimney cap with the best functions and the right aesthetic for your home. Once it’s in place, you won’t have to worry about a family of raccoons living on your smoke shelf anymore.

How Much Does a Chimney Cap Cost?

Has a squirrel, a raccoon, or a family of birds made a home in your chimney? Has water been pooling in your fireplace every time it rains? If so, either you need to install a chimney cap on your chimney, or your existing cap is damaged and needs to be replaced. The question naturally follows: how much is this going to cost me?

That’s a tough question to answer, but the good news is that we’re no stranger to chimney caps and covers at HY-C. In fact, we’ve been designing, manufacturing, and selling them since 1947. During those 75+ years, we’ve pinpointed three factors that determine the price of a chimney cap: metal type, flue size, and labor.

By the end of this article, you’ll understand how these three factors affect the price of a chimney cap. You’ll also be armed with the information you need to go into an installation consultation with clear options and a focused budget in mind.

How Metal Type Determines Chimney Cap Cost

Most of the chimney caps on the market today are made of metal. And, while the type of metal may vary from manufacturer to manufacturer, the three used most often in chimney cap construction are galvanized steel, stainless steel, and copper. Each type is weather-resistant, rust-resistant, and designed to keep animals out of your chimney. The differences between them come down simply to aesthetic and price.

Galvanized steel is the most budget-friendly chimney cap metal. Aside from its relatively low price, galvanized steel is typically treated with a black powder paint finish for a sleek, low-profile appearance.

Stainless steel tends to be more expensive than galvanized steel, but its classic, shiny metal finish proves attractive to customers who are willing to spend a little more.

Finally, copper is far and away the most expensive chimney cap metal. Its brilliant, new-penny color develops a natural patina over time, though, so if you’re looking for an eye-catching chimney cap with a premium price tag, copper is hard to beat.

How Flue Size Determines Chimney Cap Cost

Chimney Flues

After you’ve decided on the metal of your chimney cap, the next variable in determining its price is the size of your chimney’s flue. The flue is the duct that runs directly from the fireplace, up through the chimney, and out the top of the chimney crown. Flues are generally made of clay, concrete, or steel, and a chimney cap is designed to cover the portion of the flue that sticks out of the chimney itself.

Some homeowners may find that their chimney has two flues; if that’s the case, there are multi-flue chimney cap options available. But, as they are the most popular, we’ll assume you have a single-flue chimney.

How does flue size determine chimney cap cost? It’s pretty simple: the bigger the flue, the bigger — and more costly — the chimney cap. Flue sizes fall into two categories: round and rectangular (or square). Round flues have a diameter between 8” and 18”. Rectangular flues tend to measure between 9” x 5” and 20” x 20”. After you’ve measured your flue and chosen a metal, consult this table to get a general sense of how much your chimney cap will cost at retail:

5” to 12”13” to 16”17” to 20”
Galvanized steel$60 to $85$80 to $120$130 to $200
Stainless steel$100 to $140$130 to $200$180 to $280
Copper$320 to $400$360 to $430$400 to $520
Chimney cap cost estimates for round or rectangular caps made from galvanized steel, stainless steel, or copper

How Labor Determines Chimney Cap Cost

With the chimney cap metal and size in mind, there’s one last thing to figure out: how much will it cost to pay someone to install (or replace) the chimney cap? Do-it-yourself homeowners won’t need to worry about this cost factor, as they’ll be able to install the cap themselves. However, even though it may be tempting to attempt a self-installation to save some money, we do not recommend installing chimney caps yourself. It’s better to hire a trained professional with knowledge of fireplace and chimney mechanics and proven experience in roof safety.

That having been said, a few variables will affect how much you’ll pay for an installation. A simple, single-flue chimney cap installation on a single-story house may run you anywhere from $100 to $200. A more complicated installation could cost between $500 and $1,500. Why the discrepancy? Multi-story houses, high-angle roofs, or roofs with slate tile instead of shingles present more danger to the installer and, therefore, a higher bill. Depending on your home and your roof, the installer may also need to utilize specialized equipment like scissor lifts or ladders that are taller than the standard seven to ten feet.

Whatever your circumstances, be sure to get multiple quotes from a few licensed, insured chimney service professionals. Comparing these quotes will ensure you end up with competitive pricing options and will allow you to choose an installer who will complete the job safely and correctly.

Which Chimney Cap Is Best for Me?

Raccoons, squirrels, birds, and precipitation are the last things you want inside your chimney. These nuisances are annoying at best and dangerous at worst, and the most frustrating thing is knowing a simple chimney cap could have kept them out from the start.

Now that you know how metal type, flue size, and labor costs determine the price of a chimney cap, you’re ready to find one that fits the size and style of your home. After you make your purchase and hire a professional chimney cap installer, you’ll be well on your way to keeping your home safe and protected.