Chimney Cap Installation & Chase Cover Replacement in Chicago

Chimney Cap Installation in Chicago and the Suburbs

A chimney cap is the cheapest piece of hardware on your roof and the one that prevents the most expensive damage. It keeps rain out of the flue, keeps birds, squirrels, and raccoons from nesting in it, and keeps burning embers from landing on the roof. An uncapped flue takes water straight down into the smoke chamber and firebox, and that water is what eventually cracks liners, spalls brick, and rusts out dampers.

Chimney Monkey fabricates and installs stainless steel caps, chase covers, and multi-flue covers across Chicago and the surrounding suburbs. Call 847-994-4388 or request an estimate.

What Chimney Cap Installation Costs

A stainless steel masonry cap or utility cap runs about $350 installed. That covers a standard single-flue cap on a masonry chimney, or a utility cap over a furnace or water heater flue, fabricated in stainless and secured to the tile or crown.

A prefabricated fireplace cap is around $600, and the exact figure depends on the model. Prefab chimneys use a manufacturer-specific chase top and cap assembly, so the part has to match the appliance and the chase dimensions rather than coming off a shelf.

Prices move above those figures for oversized flues, multi-flue covers spanning two or more tiles, custom copper work, and chimneys that need crown or masonry repair before a cap can be anchored properly. We give you the number before we start, and we will tell you if the crown underneath needs attention first — anchoring new stainless to crumbling concrete is not a repair, it is a delay.

The 13×13 Chimney Cap, and Why Flue Size Matters

13×13 is one of the most common clay flue tile sizes in Chicago-area homes, which is why so many homeowners go looking for a “13×13 chimney cap” specifically. It is worth knowing that flue tile is described by its nominal size, and the actual outside dimensions of a 13×13 tile are usually closer to 12 3/4 by 12 3/4 inches, sometimes less after decades of weathering. A cap sold as 13×13 may or may not clamp onto your tile.

We measure the outside of the tile at the point where the cap will clamp, not the opening, and we check whether the tile projects above the crown far enough to grip. Where the tile is flush with or below the crown, a clamp-on cap has nothing to hold, and we install a crown-mounted or through-crown anchored cap instead. Multi-flue chimneys with two or three tiles of different sizes get a single fabricated cover sized to the whole crown.

Chase Covers and Chase Cover Replacement

If your chimney is a framed box wrapped in siding rather than brick, what sits on top is a chase cover — a metal pan that sheds water off the top of the chase, with a collar the flue passes through. Most builder-installed chase covers were galvanized steel, and galvanized steel in this climate has a service life measured in a decade or two.

Failed chase covers are one of the most reliable causes of interior water damage we see. The pan holds standing water at the low point instead of shedding it, the coating fails, the pan rusts through, and water runs straight down the inside of the chase into the framing and eventually into the ceiling below. The telltale signs are rust streaks running down the siding, a stain on the ceiling near the chimney, or a musty smell around the firebox.

We replace chase covers in stainless steel, custom-fabricated to your chase dimensions with a cross-break so water actually drains, a proper drip edge, and welded or sealed collar penetrations. Stainless costs more up front than another galvanized pan and does not need doing again. Chase cover repair — patching or coating an existing pan — is occasionally reasonable on a cover that has surface rust but no perforation, and we will say so if that is what we find. Once it is rusted through, replacement is the only honest answer.

My Chimney Cap Fell Off — What Now?

Caps come off for a handful of reasons: clamp screws back out or corrode, wind gets under an undersized cap, the crown the cap was anchored to has deteriorated, or the cap was simply friction-fit and never fastened. It happens most often after a storm or a hard freeze-thaw cycle.

Two things matter. First, get the flue covered reasonably soon — an open flue takes on water with every rain, and open flues are how animals get in. Second, find out why it came off, because a replacement cap installed the same way onto the same failing crown will come off again. When we come out for a missing cap we inspect the crown and the top course of masonry before quoting, and if the crown is the problem we will price crown repair alongside the cap.

If you can see the cap sitting on the roof or in the yard, leave it there and let us look at it. Homeowners going up on a roof to retrieve a cap is a bad trade at any price.

Animals, Nests, and Blocked Flues

An uncapped flue is a sheltered vertical shaft, which is exactly what chimney swifts, starlings, squirrels, and raccoons are looking for. Nesting material blocks the flue, and a blocked flue backs combustion gases into the house. If you are hearing scratching or chirping, smelling something in the room, or getting smoke rollback when you light a fire, the flue may be obstructed. We handle obstruction removal and then cap the flue so it does not recur. Note that chimney swifts are federally protected and cannot be removed while nesting, which is one more reason to cap before spring rather than after.

Stainless, Copper, and Galvanized: What We Install

We fabricate in 304 and 316 stainless steel for essentially all work. It resists the acidic condensate that comes off gas appliances, it handles Chicago winters, and it carries a lifetime warranty on most of what we install. Copper is available where the look matters, on historic homes and high-visibility chimneys, and it weathers to a patina over time. Galvanized is what most builders used and what we spend our time replacing; we do not recommend it.

Mesh sizing is a real specification, not a detail. Too coarse and it lets embers through and animals in; too fine and it clogs with creosote and soot, which chokes the draft. We size the mesh to the appliance and the fuel.

Caps, Crowns, and Liners Work as a System

The top of a chimney is a small system, and fixing one part of it while ignoring the others rarely holds. The crown sheds water off the masonry, the cap keeps water out of the flue, and the liner carries exhaust. Water that gets past the cap and crown attacks the liner and the brick from the inside, which is how a $350 problem becomes a rebuild. When we are on your roof for a cap we look at all of it and tell you what we see, including whether tuckpointing or masonry repair is coming due.

Where We Install Chimney Caps

We install caps and chase covers throughout Chicago and the north, northwest, and western suburbs, including Buffalo Grove, Deerfield, Northbrook, Glenview, Winnetka, Wilmette, Highland Park, Lake Forest, Barrington, Arlington Heights, Palatine, Evanston, Skokie, Elmhurst, Oak Brook, and Naperville. Our shop is at 741 Hastings Dr, Buffalo Grove, IL 60089. Most caps are fabricated and installed in a single visit once we have measurements.

Chimney Cap FAQs

How much does a chimney cap cost installed?

A stainless steel masonry cap or utility cap is about $350 installed. A prefabricated fireplace cap is around $600 depending on the model. Multi-flue covers, oversized flues, and custom copper cost more, and we quote those after measuring.

What size cap do I need for a 13×13 flue?

Nominal 13×13 clay tile usually measures close to 12 3/4 inches on the outside, and weathering changes that. We measure the outside of the tile where the cap clamps rather than relying on the nominal size.

How long does a chimney cap last?

Stainless steel caps carry a lifetime warranty on most of what we install. Galvanized caps and chase covers typically last ten to twenty years in this climate before rusting through.

Can a rusted chase cover be repaired instead of replaced?

Sometimes. A cover with surface rust and no perforation can occasionally be cleaned and coated. Once water is getting through, replacement in stainless is the only lasting fix.

Why does my chimney cap keep blowing off?

Usually because it is undersized, friction-fit rather than fastened, or anchored to a crown that has deteriorated. We inspect the crown and the top course of masonry before reinstalling so the replacement has something solid to hold.

Do I need a cap on a furnace or water heater flue?

Yes. A utility cap keeps rain and animals out of the appliance flue. Water in a furnace flue accelerates corrosion of the liner and can reach the appliance itself.

Do you install caps on prefabricated chimneys?

Yes. Prefab chimneys use a manufacturer-specific chase top and cap assembly, so we need the model information from the appliance plate to order the right part.