Inspection Unit 3D

Types of Inspections

Chimney Inspections

Chimneys are a special concern. Inspection consists of looking at the chimney exterior, then in the flue(s) from the top and the bottom. First, look at the exterior of the chimney and how it is positioned by the house. Keep an eye out for two key problems. First, chimneys pull away from the building, creating a gap that bats in particular love to exploit. Second, the slate part of the chimney often slides away from the building, creating a gap that squirrels reportedly love to use. Some have even seen gray squirrels chew an opening if the slate is loose.

Next, you will need to investigate the inside of the chimney. But first, ask your client how many fireplaces the building has. Each fireplace and furnace will have its own flue. A chimney can have more than one flue. Don’t confuse chimneys with flues. In the photo below, one chimney cap is broken and the second flue (partially shown in the lower right corner) does not have a cap (photo by Stephen Vantassel).

The photo below (courtesy of Stephen Vantassel) shows double walled metal flues. The inside flue is screened but notice that the exterior tube is not.

Many birds and squirrels do fall in between the two pipes. Note that they look screened. But there is a gap at the base that allows birds and other animals to squeeze in and become trapped. Make sure to ask if there are any fireplaces in the basement. People tend to forget how many fireplaces they have if they don’t use them.

Always inspect a chimney from the top first. If it isn’t a bent flue, it can save you from looking up from the bottom. As you look down the flue, take a moment and look for smudge marks that will alert you to previous and/or present raccoon occupation. When you are inspecting from the top of the chimney, look for spider webs in the flue. The presence of spider webs will tell you that nothing has gone down this chimney in a while. Even though raccoons rarely enter active furnace flues, it has been known to happen. So pay attention. Occasionally, you will even find bits of fur caught in the cracks of rough flue tile. Always inspect a chimney from the top first. You don’t want to be surprised by an animal when you open the damper.

Don’t take the client’s word that the flues have been screened. Screening rusts through or blows off. These homemade screening jobs are usually illegal as they don’t allow enough clearance for exhaust. (See picture. The black cap is the right way. The hardware cloth is the wrong way. Photo by Stephen Vantassel). Make sure your eyeballs do the job. A chimney can have more than one flue and not all flues can be seen from the ground as demonstrated by the first image on the page.

Checking fireplaces on the inside: Since old fireplaces are full of soot and other materials, don eye and respiratory protection. (You will also need your reflecting mirror so you can look behind the damper.)

If you must open the damper, always open the damper slowly and no more than an inch at first. But first don your HEPA filter respirator and goggles to protect your lungs and eyes from falling debris. Shine your flashlight into the crack and look for any paws and fur. Listen for noises. You don’t want to be surprised and have a soot-covered squirrel run around your customer’s picture-perfect white-carpeted living room. I like to prime the flue with a propane torch. This way the draft is going up when I crack the damper. I like using propane because it doesn’t create smoke and the flame can be turned out immediately. You won’t burn the animals if you keep the flame away from the damper. The smell of the propane has the added advantage of spooking animals like raccoons that will often begin climbing the chimney away from the damper. Although during most of your inspections you will not find animals, here are some rules of thumb regarding noises emanating from a chimney: 1) Scratching, think squirrel. 2) Fluttering, think bird. 3) Chirping, think raccoon. 4) Grinding noise, think chimney swift (especially if the chimney is not lined with tile.) Don’t be surprised if other animals are found in the chimney. I personally have found a duck and an owl, so the list of animals can get pretty strange.

Finally, recommend that the customer have the chimney secured with a professional and code-compliant chimney cap. But NEVER, NEVER secure the chimney unless you are certain that there are no animals inside. The image at right shows a professionally capped chimney with a multi-flue cap.  (Photo by Hy-C Co., Inc.)


Stephen M. Vantassel, Wildlife Removal Handbook Rev. (Stephen M. Vantassel, 1999).

Stephen M. Vantassel. Wildife Damage Inspection Handbook 3rd. ed. (Lincoln, NE: Wildlife Control Consultant, 2012).

©2005 Stephen M. Vantassel

Unit 4A