How much does a chimney cap replacement cost in St. Louis?

It depends on three things: how many flues the chimney has, the outside measurement of the tile, and whether you need a single-flue cap or a full multi-flue cover. A standard single-flue stainless cap is the low end; a fabricated multi-flue cover for a wide masonry chimney is several times that. We measure first and give you the number before anything is ordered — we do not quote caps sight unseen.

Stainless steel or galvanized — which should I get?

Galvanized costs less on day one and rusts out in roughly five to ten years in Missouri weather, because the freeze-thaw and the acidic flue gases eat the coating. Stainless costs more up front and generally outlasts the homeowner. Most of the caps we take off are rusted galvanized lids, which tells you most of what you need to know.

My cap blew off in a storm. Is that an insurance claim?

Often yes — wind damage to a chimney cap or chase cover is usually covered under a standard homeowner policy, and a missing cap after a storm is easy to document. We photograph the chimney before and after and give you the images and a written scope for the adjuster. See our storm damage page.

Does every flue need its own cap?

Every open flue needs to be covered — the fireplace flue, and any separate flue serving a furnace or a water heater. A chimney with three flues and one cap has two open drains in it. On multi-flue chimneys a single fabricated cover over the whole crown is usually cheaper and neater than three separate caps.

Chimney Cap Replacement St. Louis

What a Chimney Cap Does — and Why Yours Failed

The cap is the lid over the top of your flue. It keeps rain and snow out of the chimney, keeps birds and raccoons from nesting inside it, keeps sparks off the roof, and stops the downdraft that pushes cold air and smoke smell back into the room. It is a small piece of metal doing four jobs at once, and it is the first part of the chimney to give out.

New stainless chimney cap installed on a chase cover in St. Louis, MO — A new cap set on a chase cover — the finished result on a St. Louis chimney.

Rain Is the Expensive Part

An open flue is a drain pointed straight into your house. Water gets into the clay liner and freezes in the joints, rusts the damper shut, soaks the smoke chamber, and eventually shows up as a stain on the ceiling next to the fireplace. By the time a homeowner in St. Louis calls us about that stain, the repair is rarely just a cap — it is a cap plus a liner or a crown. Replacing the cap early is the cheapest chimney work there is.

Birds, Raccoons and Squirrels

An uncapped flue is a dry, warm, predator-free shaft, which is exactly what a raccoon wants in February and what chimney swifts want in May. Nesting material packed into a flue is a blockage, and a blockage on a working fireplace or a furnace flue is a carbon monoxide problem, not just a noise problem. If something is already living up there, we handle the removal before the cap goes on — see chimney animal removal.

A Cap and a Chase Cover Are Not the Same Part

On a masonry chimney, the cap sits over the clay flue tile. On a factory-built or prefab chimney, the whole top of the chase is closed by a large sheet-metal lid called a chase cover, with the cap sitting on top of that. People call both of them "the cap", and the two cost very different amounts. If yours is a prefab chase, read stainless vs galvanized chase covers before you buy anything. When we replace a chase cover we fabricate it in stainless to your dimensions, and that cover carries a lifetime warranty.

New stainless steel chase cover with a cross break and a new chimney cap, St. Louis MO — Cap and chase cover are two different parts. Here both were replaced — stainless cover with a cross break, new cap on top.

🔎 Check from the ground: rust streaks running down the brick, or dark staining across the crown, almost always means the cap or the chase cover has already rusted through.

What We Find on a Failed Cap

Galvanized lid rusted through

Cap blown off in a storm

Mesh bent, crushed or torn open

Slip-in cap loose — set screws backed out

Multi-flue chimney with no cover at all

Cracked crown under the cap

Nesting material packed into the flue

Cap sized for the wrong flue

How the Replacement Goes

We measure the flue — outside dimensions of the tile, or the full chase opening on a prefab — and check the crown underneath while we are up there, because a new cap bolted onto a cracked crown just hides the leak. Standard single-flue caps we carry and fit the same visit. Multi-flue covers are fabricated to the measurement, so those run a few days. Either way you get photographs of the old part and the new one.

Masonry chimney with a rebuilt crown and a new stainless rain cap sized to the flue, St. Louis MO — Masonry chimney after a crown rebuild, with a new stainless rain cap sized to the flue tile.

What Decides the Price

There is no single price for a chimney cap, and anyone quoting one over the phone before seeing the chimney is guessing. Five things move the number:

Multi-flue masonry chimney with two new stainless top-mount damper caps installed, Wentzville MO — Two flues means two caps. Flue count and size are the first thing that moves the price.

Single flue or multi-flue — one lid, or a fabricated cover over the whole crown

Flue size — measured outside the clay tile, not inside

Material — galvanized, stainless, or copper

Height and access — a single-storey ranch is not a three-storey roof

Crown condition — a cracked crown under the cap has to be dealt with first

We measure on site, tell you the number before anything is ordered, and you decide. Standard single-flue caps we carry on the van and fit the same visit.

Related services: if water has already got in, start with chimney leak repair or a camera inspection. Storm damage to a cap is often an insurance claim — see storm damage. Crown and mortar work is covered under tuckpointing.

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