Every fall we check Oakville rooflines where the vents are covered, the soffits are sound and the attic is quiet — and then find the one opening nobody thought about: an uncapped chimney, wide open at the top. To you it is a flue. To a raccoon it is a hollow tree with a warm room at the bottom.
Why a chimney is a raccoon's ideal den
A raccoon does not need an invitation, just an opening it can climb down. The inside of a flue is rough enough to climb easily, the smoke shelf above the damper is a flat, sheltered ledge, and the whole stack is dark, dry, protected from wind and predators, and warmed every time the furnace runs. In the wild that combination is a den tree. In Oakville — older brick chimneys, mature trees overhanging the roofline, weathered flashing where the chimney meets the roof — it is available on street after street.
That is why chimney work is a core part of our raccoon removal calls around wildlife removal in Oakville. A mother raccoon will choose a chimney as a maternity den in spring: the young stay in the flue until they are old enough to climb, and the homeowner below hears the whole family without ever seeing an entry hole — because there isn't one in the roof. The door was at the top of the chimney the whole time.
Ontario's own guidance on preventing conflicts with small animals starts from the same place: secure the openings and remove the welcome mat, and most wildlife problems never start. An uncapped flue is the welcome mat nobody checks.
The signs a raccoon is living in your chimney
A chimney den is easy to miss from the ground and hard to miss once you know what to listen for:
Thumping, scratching and chattering from the fireplace. Sounds that seem to come from inside the wall or behind the damper, strongest at night and around dawn, are an animal climbing and settling in the flue — not in the attic.
Chirping or crying in spring. Young raccoons in a chimney den call for their mother. If you hear it from the fireplace, there is a family in the stack.
A strong smell near the fireplace. Droppings and urine collect on the smoke shelf. A denning raccoon produces a constant smell around the hearth, not a one-night whiff.
Muddy, hand-like prints on the roof. Raccoon prints look like small human hands. Prints around the chimney base, and scuffed or lifted flashing where the chimney meets the roof, show the route in.
A cap that is there — but moved, bent or loose. A raccoon that found a weak cap will work it. A cap sitting crooked, screening peeled back, or a flue cover on the roof beside the chimney means something already tested it and got in.
What not to do — three dangerous shortcuts
The first is lighting a fire to smoke it out. Never do this. An animal in the flue — especially young that cannot yet climb — can be killed by smoke and heat, a nest in the chimney is a chimney-fire risk, and a panicked adult raccoon comes one of two ways: up, or down through the damper into your living room.
The second is capping or sealing the chimney the moment you suspect something. If a mother is out feeding and her young are on the smoke shelf, a cap locks her out and them in. She will tear at the roof and flashing trying to reach them, and the young will die inside the flue. No cap goes on until the chimney is confirmed empty — that order is not negotiable.
The third is trusting a cheap cap or DIY screening. Raccoons have dexterous hands and real strength. Light screening gets peeled back, a friction-fit cover gets lifted, and a loosely fastened cap gets worked until it moves. A chimney cap only works if a raccoon cannot lift, pry or tear past it — heavy-gauge, properly sized to the flue, and fastened down, not just set in place.
Chimney cap raccoon prevention: how the job is actually done
The order matters as much as the hardware:
Inspect first. We confirm what is in the chimney and whether young are present, check the smoke shelf and damper, and inspect the flashing and gaps where the chimney meets the roof — raccoons use those too.
Get the animal out humanely. An adult with no young is encouraged out and kept out with a one-way door fitted at the chimney, so it leaves on its own and cannot re-enter. Where there are young, timing and handling keep the family together — no exclusion proceeds until the young can leave with their mother.
Clean the flue shelf. Droppings and nesting material left on the smoke shelf keep attracting attention and keep smelling. The den site is cleaned as part of closing it.
Fit a proper cap. Once the chimney is confirmed empty, a heavy-gauge metal cap, sized to the flue and securely fastened, goes on — mesh that lets smoke escape freely while giving a raccoon nothing to grip, lift or tear. Inside-mount and top-mount styles both work when they are the right size and properly fixed; a loose fit of either kind does not.
Seal the rest of the stack. Gaps at the chimney base and damaged flashing are sealed in the same visit, because closing the flue while leaving the flashing open just moves the entry point a foot to the side.
Done in that order, the chimney stops being a den and goes back to being a chimney — and the raccoon moves on to an actual hollow tree.
How Regional Wildlife Services handles it
Regional Wildlife Services is owner-operated: Sean Thornton, 20+ years removing wildlife humanely, does the inspection and the work himself. That matters on a chimney job, where the decision — cap now, or wait for young to grow — has to be made by the person looking into the flue. Get the animal out humanely, keep families together, then close the opening properly.
Frequently asked questions
How do I know if it is a raccoon and not birds?
Listen and look. Birds flutter and chirp in daylight and come and go from the top. A raccoon is heavy: thumping and scratching, mostly at night, a strong smell at the fireplace, and hand-like prints on the roof. An inspection confirms the animal before any work starts, because the timing rules are different for each.
Can I just buy a cap at the hardware store and put it on this weekend?
Only if you are certain the chimney is empty — and from the ground, you usually cannot be. A cap installed over a family seals them in. The cap itself also has to be heavy-gauge, correctly sized and fastened down; a light, loose cap is one a raccoon can lift. If there is any sign of current use, have the chimney checked first.
What happens in spring if there are babies in the chimney?
The family stays together. Young raccoons cannot climb out for their first weeks, so exclusion waits or is handled so the mother and young are reunited outside — never separated by a cap. Once the young are mobile, the family is moved out humanely and the cap goes on.
Will a chimney cap affect my fireplace or furnace?
A properly fitted cap is designed to let smoke and exhaust escape while blocking animals, debris and rain. That is exactly why sizing and fitting matter — a cap is matched to the flue, not forced over it.
Which towns do you serve?
Oakville and across the region — Burlington, Milton, Hamilton, Stoney Creek, Niagara and Georgetown.
When did you last look at the top of your chimney?
Call Regional Wildlife Services at 905-320-8984. We take phone calls and bookings 7 days a week; service appointments run Monday to Friday typically, and weekend calls book jobs in for the following week. We serve Oakville, Burlington, Milton, Hamilton, Stoney Creek, Niagara and Georgetown. An open flue is an open door — close it properly, after it is confirmed empty: contact us.
