Caps, Crowns & Chase Covers
Three different parts, three different jobs, and constantly confused for one another. All three sit at the top of the chimney and all three are what keep water out of it.
Stainless and copper as standard. Galvanised rusts through and we have seen it too often.
What we fit and repair
- Single and multi-flue stainless caps
- Poured and reinforced crown rebuilds
- Crown sealing and crack repair
- Stainless chase covers, custom fabricated
- Top-sealing dampers
- Animal guards and spark arrestors
Cap, crown and chase cover are not the same thing
This trips up almost everyone, including some contractors. Knowing which part you are looking at tells you whether you are facing a couple of hundred dollars or a couple of thousand.
The cap
A metal cover that sits on top of the flue opening itself, held clear on legs, usually with mesh sides. It blocks rain, keeps animals out of the flue, catches sparks and helps with downdraft.
The crown
The concrete or mortar slab that covers the whole top of a masonry chimney, around the flue tiles. It sheds water off the brickwork below. It is structural, not an accessory.
The chase cover
The metal lid on top of a framed and sided chase, which is what you have if your chimney is a wood-framed box rather than masonry. It does the crown's job in sheet metal.
The cheapest part of the chimney and the one that saves the most money
An uncapped flue is an open pipe into your house. Every rainfall goes straight down it onto the smoke shelf and damper, and every spring a starling or a grey squirrel decides it looks like a good place to raise a family.
We fit stainless and copper caps sized to the flue, with mesh that keeps animals out without choking the draft. Multi-flue caps cover the whole crown on a stack serving several flues, which has the useful side effect of protecting the crown itself from direct rain.
Where downdraft is the complaint rather than water, there are cap designs specifically shaped to deal with wind coming off a nearby roof or ridge, and they work far better than people expect.
- Keeps rain out of the flue, damper and firebox
- Stops birds, squirrels, raccoons and nesting material
- Contains sparks and embers leaving the flue
- Reduces wind-driven downdraft into the room
- Protects the crown from direct rainfall
- Cheapest single improvement you can make to a chimney
Where most masonry chimneys are failing right now
A crown should be a poured concrete slab, reinforced, sloped away from the flue tiles so water runs off, and overhanging the brick by an inch or two with a drip edge cut into the underside so water drips clear rather than tracking back onto the masonry. There should also be a flexible joint where it meets the flue tile, because the two materials expand at different rates.
What we find on most Chester County chimneys is none of that. A thin mortar wash, laid flat, flush with the brick face, cracked right through and bonded hard to the tile. Water sits on it, runs into the cracks, and enters the top of the stack where it does the most damage.
- Visible cracks running across the crown surface
- The crown flush with the brick, with no overhang or drip edge
- A flat crown with standing water or debris on it after rain
- Crumbling or missing sections around the flue tile
- Gaps opened up where the crown meets the flue tile
If your chimney is a sided box, this is your crown
Prefabricated and factory-built fireplaces are usually housed in a framed chase clad in siding, brick veneer or stucco. The metal lid on top is the chase cover, and on a great many homes built through the 1980s and 1990s it was fitted in galvanised steel.
Galvanised rusts. Worse, most of them were made flat, so water pools on the surface instead of running off, and the rust starts in the middle of the pan where nobody can see it. By the time rust stains are running down the siding, water has been getting into the chase for a while.
We fabricate replacement covers in stainless, cut to the chase, with a cross break so water sheds, correctly sized flue collars, and a drip edge over the siding.
- Rust-coloured streaks running down the siding or brick veneer
- Standing water visible on the cover after rain
- Any rust holes, however small, in the pan
- Cover sitting flat rather than crowned or cross broken
- Gaps or failed sealant around the flue collars
- Cover flapping or lifting in wind
Tops of chimneys, answered
How much does a chimney cap cost?
A single-flue stainless cap fitted is one of the least expensive things we do. Multi-flue covers, custom sizes and copper cost more. We quote before we order, and there is no charge for looking.
A cap blew off in a storm. Is that normal?
It is common with friction-fit caps on a flue that has weathered, or where the original fit was marginal. Replacements should be properly secured. If the same cap has gone twice, the fit is the problem, not the wind.
Is a chimney cap required by code?
Requirements vary by jurisdiction and by appliance. In practice, spark arrestor screening is required in many situations, and no inspector or insurer is going to be pleased about an open flue. It is a small cost with an outsized benefit.
Can I seal my own crown?
The coatings are available and the work is not complicated, but it is on a roof at the top of a chimney, and the diagnosis matters more than the application. Sealing a crown that actually needs rebuilding buys you a season.
There are birds in my chimney. Can you just cap it?
Not straight away. Chimney swifts are federally protected while nesting, and capping a flue with animals inside creates a worse problem than the one you started with. We deal with the flue first, then cap it so it does not happen again.
Everything else we handle on the chimney
Most of our visits turn up more than one thing. Because we do the cleaning, the masonry, the liner work and the waterproofing ourselves, you are never handed off to a second contractor.
Serving Chester County and the surrounding townships
We work out of Chester County and cover the boroughs, townships and rural stretches around it. Pick your town for local detail, or call and we will tell you straight away whether you are on our route.
Get the top of your chimney sorted
Caps, crown repair and rebuilds, and custom stainless chase covers across Chester County.