Chimney Cap Installation

Chimney Monkey measures and installs chimney caps across Chicago’s North Shore. A cap covers the flue opening to help keep rain, animals and debris out. The correct replacement depends on the chimney type, actual measurements and the condition of the mounting surface.

Request a cap assessment or call 847-994-4388. Tell us whether the cap is missing, loose, rusting or damaged. We will confirm the visit scope; diagnostic inspections are paid and installation is quoted separately.

Cap, termination or chase cover?

• Masonry flue cap: sized to the actual flue tile or mounting surface. A multi-flue cap may cover more than one opening.
• Factory-built termination: the fireplace and chimney system determine the compatible component. A generic masonry cap is not automatically a suitable replacement.
• Framed-chase cover: the metal cover sheds water off the top of the enclosure. It is a different part from the cap above the flue. See chase cover installation and replacement.

If a cap has fallen off

Replacing the cap is only part of the assessment. We check the fit, attachment points and supporting tile, crown or masonry. If the mounting surface has deteriorated, that work needs to be defined before a replacement can be secured.

Tell us if you hear animals or suspect an obstruction. A cap does not remove a blockage, and a flue should be checked before it is covered. Photos from ground level can help explain the problem; you do not need to climb onto the roof.

Measurement, options and installation

We measure the actual opening and review access, mounting condition and suitable materials before quoting. Stainless steel, copper and custom or multi-flue options depend on the chimney and project. Stock availability and fabrication needs determine whether installation can happen during the assessment or requires another visit.

A cap is not a cure for every leak or smoke problem. If water is already entering, start with chimney leak diagnosis; if the chimney’s condition is uncertain, ask about a paid inspection.

Proudly Serving Chicago’s North Shore

Based in Buffalo Grove, Chimney Monkey serves the North Shore and nearby communities listed below. Contact us to confirm service for your address.

Core Service Areas

Specifically, we proudly serve Evanston, Wilmette, Kenilworth, Winnetka, Glencoe, Highland Park, Highwood, Lake Forest, Lake Bluff, Deerfield, Riverwoods, Bannockburn, Northfield, Northbrook.

Extended Service Areas

We also cover Arlington Heights, Barrington, Buffalo Grove, Des Plaines, Glenview, Hawthorn Woods, & Fort Sheridan.

📞 Call Chimney Monkey at (847) 994-4388 and let us take care of your chimney needs!

What a Chimney Cap Actually Does

A chimney cap is a small piece of metal doing four jobs at once, and it is the cheapest insurance on the entire chimney. It keeps rain out of the flue, which matters more than most homeowners realise because water inside a chimney destroys mortar joints, rusts the damper, and can saturate a liner from the inside. It keeps animals out, which in this area means squirrels, raccoons, chimney swifts, and starlings that will nest in an open flue given a single season. It stops downdrafts from pushing smoke and odour back into the room. And the spark arrestor screen keeps burning embers from landing on your roof.

An uncapped flue is the single most common defect we find on inspections, and it is almost always the cheapest thing on the report to fix.

Chimney Caps and Chase Covers Are Not the Same Thing

People use these terms interchangeably and they are entirely different components. A chimney cap sits on top of the flue itself, covering the opening. A chase cover is the large metal pan that covers the entire top of a framed chimney chase, the kind you find on homes with prefabricated or factory-built fireplaces. The chase cover is essentially a lid over the whole box, and the cap sits on the flue pipe that comes through it.

Chase covers fail in a predictable way. Most were built from galvanized steel, they sit flat instead of sloped, water pools in the middle, and after fifteen or twenty years they rust through. You will see rust streaks running down the siding long before there is a visible hole. Once it perforates, water goes straight into the chase and into the framing. Replacement chase covers should be stainless steel with a proper slope and a cross break so water sheds instead of standing.

Sizing: Standard Flue Dimensions and Why 13×13 Comes Up So Often

Clay flue tiles come in standard nominal sizes, and 13×13 is one of the most common in Chicago-area masonry chimneys, along with 8×8, 8×12, 12×12, and 13×18. The complication is that nominal size and actual outside dimension are not the same number, and a cap has to fit the outside of the tile, not the nominal label. Older tiles also vary from their stated size, and a chimney that has been repointed or had the crown rebuilt may have mortar encroaching on the tile.

This is why we measure rather than guess. A cap ordered off a nominal number and shipped to the house frequently does not fit, and a cap that does not fit either blows off in a storm or gets forced on in a way that cracks the tile. We measure the actual flue on site and size the cap to it.

Materials: Stainless, Copper, and Galvanized

Galvanized steel is the cheapest option and the one we generally advise against. It rusts, usually within a decade in this climate, and then you pay twice. Stainless steel is what we install in most cases: it holds up to Chicago freeze-thaw cycles and roof runoff, it does not stain the masonry, and a good stainless cap will outlast the homeowner. Copper is the premium choice and is worth it on homes where the chimney is visible and the architecture justifies it, which on the North Shore is a lot of them. Copper weathers to a patina rather than corroding.

Multi-Flue Caps and Custom Work

Many older homes here have two, three, or four flues coming through one crown — a fireplace, a furnace, a water heater, sometimes a second fireplace. You can cap each one individually, or install a single multi-flue cap that covers the whole crown. A multi-flue cap usually looks better, protects the crown itself from rain, and is often the more sensible option when the crown is already deteriorating. It has to be fabricated to the actual crown dimensions, so it is a measure-first job.

Signs You Need a Cap or a Replacement

Look for an open flue with nothing on top of it, a cap that is visibly rusted, dented, or sitting crooked, missing or torn spark arrestor mesh, rust streaks running down the chimney or the siding below the chase, water stains on the ceiling or wall near the chimney, a damp or musty smell from the fireplace after rain, or the sound of animals in the flue. Any of these is worth a look before winter.

Cost and Scheduling

Cap and chase cover pricing depends on the size of the flue or chase, the material you choose, whether the piece is stock or has to be fabricated, and roof access. Because a cap has to fit the actual opening, we measure before quoting rather than giving a number over the phone that changes when we arrive.

The efficient way to handle it is to have the cap looked at during a chimney sweep or inspection, since we are already on the roof with access to the crown. Call 847-994-4388 to schedule, and mention that you want the cap assessed.

Chimney Caps From Our Job Records

These photos come from our own job records across Chicago's North Shore and nearby suburbs: caps as we found them, and caps we have installed or replaced on single-flue, multi-flue and factory-built chimneys. Each caption names the town and street. We don't publish house numbers.

Caps as we found them

Caps on chimneys we have worked on

Chimney Cap FAQs

What size chimney cap do I need?

It depends on the actual outside dimensions of your flue tile, not the nominal size. Common Chicago-area flues include 8×8, 8×12, 12×12, 13×13, and 13×18, but real-world measurements vary and mortar from repointing can change the fit. We measure on site and size the cap to what is actually there.

What is the difference between a chimney cap and a chase cover?

A cap covers the flue opening itself. A chase cover is the large metal pan covering the entire top of a framed chimney chase on homes with prefabricated fireplaces. Many homes need both, and they fail for different reasons.

How long does a chimney cap last?

A quality stainless steel cap should last decades. Galvanized steel typically rusts through within about ten years in this climate, which is why we usually recommend against it.

Do I really need a chimney cap?

Yes. An open flue lets in rain, animals, and debris, and lets embers out onto the roof. Water intrusion is the leading cause of chimney deterioration in this region, and a cap is the least expensive way to prevent it.

Can you install a cap during a chimney sweep?

Often, yes, if it is a stock size we carry. Custom and multi-flue caps have to be measured and fabricated, so those take a second visit. Either way we can assess it during a sweep or inspection.

Why is there rust running down my chimney?

That is usually a failing galvanized chase cover. Water pools on the flat pan, rust forms, and runoff carries the stain down the siding. It generally means the cover is near the end of its life and should be replaced with a sloped stainless one before it perforates.

What a chimney cap costs

A standard stainless steel cap with spark arrestor typically runs $320 to $500 installed, depending on flue size. Multi-flue caps run $820 to $1,000, caps for factory-built fireplaces $650 to $950, and decorative caps and toppers $1,075 to $1,700 depending on material. The exact price is confirmed in writing before any work begins. Current ranges for every service are on our service cost guide.