Preventing Animals from Entering Your Chimney

Nov 22, 2022

Animals need a comfortable place to shelter from predators and weather that’s too hot, cold, or rainy. Unfortunately, wild animals might choose your chimney as their safe place, which will make your home less safe for you.

Luckily, with some expert advice and help from chimney professionals, you can prevent animals from entering your chimney.

What Kind of Animals Get Into Chimneys?

Some animals are more likely to seek shelter in your chimney than others, as they’re good at climbing (or flying) and can squeeze through small openings, such as:

  • Bats
  • Squirrels
  • Birds
  • Rats & mice
  • Raccoons

Dangers of Animals in Chimneys

Having an animal nest in your chimney introduces several significant safety hazards, including:

Bad Ventilation
Chimneys are designed to have a specific type of airflow, with enough air to fuel the fire and enough air escaping to vent harmful fumes and smoke. With an animal nest blocking chimney ventilation, excess smoke could cause or exacerbate respiratory issues, or fume buildup could lead to carbon monoxide poisoning.

Fire Hazard
Nests tend to be made from flammable materials that can ignite when heat rises inside a blocked chimney, and the resulting fire would put your home and family at risk.

Disease Risk
Animals carry parasites and diseases like rabies, the plague, or the hantavirus, which is present in feces, urine, and saliva. Even if you avoid touching these secretions, an infection can result from breathing in the dust from dried particles.


How Can I Stop Animals From Entering My Chimney?

With expert advice and assistance, you can prevent animals from nesting in your chimney. Consider the following preventions to avoid animals entering your chimney:

Install Or Repair Your Chimney Cap

A chimney cap rests a few inches above the chimney with a screen or fine mesh blocking the gap between. It’s an effective barrier that allows for good ventilation and airflow.

Chimney caps also reduce downdrafts and block twigs and leaves from falling inside and onto the damper, where they could cause damage or a blockage. They also keep out precipitation that could cause water damage or form creosote. Created when soot and moisture mix, creosote has a strong, unpleasant odor and is caustic enough to deteriorate a chimney liner.

Schedule Annual Chimney Inspections, Cleaning & Maintenance
With annual chimney inspections and cleanings , you’ll stay on top of issues that make your chimney vulnerable to animals. Cleaning and maintenance also clear out creosote buildup, debris, and nests. These preventative measures will preserve your chimney and prevent unnecessary health and safety risks.

For over 30 years, has delivered the best local chimney sweeping, restoration, repair, damper replacement, and more.

To schedule a service or for more info call (408) 265-1010 or contact us on-line.

Smoking back

There are many fireplaces that seem to smoke back into the house no matter what is done. In our experience, the most common cause is that the fireplace simply needs to be cleaned. This is especially likely if the fireplace has gotten worse over time, that is, the smoking back is worse now than it used to be.

Several other possible causes of smoking back are problems with the damper, chimney cap, grate, firewood, or structural problems with the chimney itself. At Chimney Clean Company, we do a full inspection with every cleaning, or we can also do just the inspection if the chimney doesn’t need to be cleaned. This inspection is designed to reveal any causes of smoking back.

Broken chimneys

In the Bay Area, many chimneys were broken in the 1989 Loma Prieta earthquake. Usually, these chimneys are broken at or near the roof line, although sometimes they can be broken further down, even at the ground level.

We are fully licensed masonry contractors. We rebuild broken chimneys. If they are broken at the roof line, this usually entails taking the chimney part of the way down brick by brick, installing steel reinforcing bars, getting an inspection from a city inspector, then rebuilding the chimney back up around the steel rebar.

Missing mortar or damaged bricks

Over time, many chimneys develop places that are missing mortar between bricks, or damaged bricks, either inside the firebox or on the outside of the chimney. These areas can usually be repaired, either by replacing the missing mortar or replacing the bricks themselves. Items such as these can be dangerous because they can allow flames, sparks or hot gases to enter the structure of the house.

Water entry

Sometimes the metal that seals the chimney at the roof, called “flashing”, will come loose or develop leaks. In this case, water sometimes comes into the ceiling of the room and causes water spots and stains on the sheet rock. This flashing should be repaired before the water causes more damage.