Chimney chase cover installation for framed, sided chimneys
Chimney chase cover installation replaces the sheet-metal lid on a wood-framed chimney box, the kind built around a factory-made fireplace flue, with a sloped cover that throws rain off the edges. The New Bedford office at 227 Union Street handles chase tops on houses in the city and in Dartmouth, Acushnet and Fairhaven, checking the framing beneath before anything is ordered.
Where chases turn up here, and why their tops corrode
Most chimneys in the older neighborhoods are brick. Framed chases belong mostly to later construction, and near the coast their metal tops have a hard life.
Later houses, factory-built fireplaces
A chase is typically part of a prefabricated fireplace system, so you are more likely to find one on a house from the later decades of the 20th century or newer, such as the 1980s and 1990s homes that make up a share of Dartmouth.
Salt on thin sheet metal
Salt carried on wind off the bay settles on chase tops and eats at the thin galvanized steel builders often used. Pinholes and rust streaks appear sooner on houses that face the water.
Snow and standing water
A flat lid holds puddles after rain and slush after a nor’easter. Water left sitting on steel speeds corrosion, and freezing nights flex the metal around its fasteners until gaps open.
Housing ages, heating fuels and storm history come from the sourced notes on our community pages: New Bedford, Dartmouth, Fairhaven, Acushnet.
How a chase top gets replaced
The cover is only the visible part. Before measuring, we check what water may already have done to the framing, siding and metal flue under it.
Inspect the whole top
From the roof we look over the old lid, the storm collar, the cap, the uppermost run of siding on the box and the flue pipe where it passes through, and photograph what we find.
Measure for a made-to-fit cover
Each side of the chase is measured so the new cover overlaps the siding with a skirt and a drip edge all the way around, with the flue hole placed exactly.
Take off the failed lid
The old cover is unfastened and lifted away, and the plywood or framing beneath is probed for soft, rotted wood that would not hold the new one.
Set the sloped cover
A cover raised or cross-broken in the middle, in stainless steel or another durable metal, is set in place and fastened through its side skirt rather than through the top.
Seal around the flue
A storm collar closes the gap where the flue pipe comes through, and the cap is refitted or replaced so the whole top matches.
If the framing or siding under the lid has rotted, that is carpentry; we show you the damage and it may call for another trade.
Factory-built fireplaces are listed systems, so any work on the flue itself follows the manufacturer’s instructions and parts.
Telltales of a failing chase top
You can spot most of these from the driveway or inside near the fireplace.
- Brown streaks on the sidingRust running down the outside of the chase from the top edge is the most common giveaway.
- A lid that dips in the middleA sagging or dented top collects water instead of shedding it, and corrodes faster as a result.
- Stains by the fireplace after rainMarks on walls or the ceiling around a prefabricated fireplace often trace back to water entering at the chase top.
- Rust inside the fireboxOrange stains on the metal panels of a factory-built unit mean water is reaching it from above.
- A gap around the flue pipeA missing or loose storm collar leaves an open ring where rain can run straight down into the box.
Chase cover, crown or cap?
This service is for a chimney that is sided and framed like a wall of the house, with a metal top. A brick or stone chimney has a masonry crown instead, and the repair is different.
Ask for chase cover installation when
- Rust is streaking down the siding of the chase
- The metal top is flat, dished or holed
- Water stains appear near a factory-built fireplace
- The collar around the flue pipe is loose or gone
Ask about a different page when
- A brick chimney with a broken top slab: Chimney Crown Repair
- A brick flue left uncovered: Chimney Cap Installation
- Water is coming in and the source is unclear: Chimney Leak Repair
What changes the size of a chase cover job
Covers are usually made to measure, and what turns up under the old one can add work. These are the main variables.
- Dimensions and flue count
- A wide chase, or one with two flue pipes coming through, needs a larger cover with more openings and more careful layout.
- The metal chosen
- Stainless steel and copper outlast galvanized steel by a wide margin near salt water, and they cost more to buy and form.
- Condition under the lid
- Soft plywood, rotted framing or loose siding at the top has to be dealt with before a new cover can be fastened.
- Collar and cap at the same time
- When the lid has failed, the storm collar and cap are often worn too, and replacing them together adds parts to the job.
- Roof height and pitch
- Working on a tall chase over a steep roof is slower to set up safely than a short box on a gentle slope, with taller ladders and roof anchors.
No price list on this site, on purpose. Two chimneys that sound the same over the phone rarely are. Once someone from the New Bedford office has looked at yours, you get the scope in writing and decide from there.
Chase cover questions people ask us
How can I tell whether my chimney is a chase?
Look at it from the yard. A chase is wrapped in the same siding as the house, or something like it, and has a metal top. A masonry chimney shows brick or stone all the way up and finishes in a concrete or mortar crown. If you are unsure, a photo sent with your request usually settles it.
Can I paint a rusty chase cover instead?
Paint can slow surface rust on a lid that is still sound and properly sloped. It does nothing for a flat or sagging top that holds water, and it will not close holes that have already rusted through. In those cases a new sloped cover is the repair that lasts.
What does the drip edge do?
It is a small bend at the bottom of the cover’s skirt that kicks water away from the siding. Without it, rain runs off the top and down the face of the chase, where it can work in behind the siding and soak the framing.
Will the rust stains on my siding go away?
A new cover stops fresh rust from running down. Stains already on the siding may or may not clean off, depending on the material and how long they have been there. We tell you what we expect before the work, not after.
Should the fireplace be checked as well?
If water has been getting into the chase, yes. It can corrode the metal flue and damage parts of the fireplace unit. We look at what can be reached and tell you if anything needs attention under the fireplace maker’s instructions.
Booking, hours and general chimney questions are on the main FAQ; how a visit runs is on what to expect.
Often looked at alongside
- Chimney Cap InstallationMeasuring each flue and fixing a screened stainless or copper hood over it against weather and wildlife.
- Chimney Leak RepairTracing water to the crown, cap, flashing, brick or flue where it enters, then repairing that source.
- Chimney InspectionA yearly check of the firebox, damper, flue and chimney top, with photographs and a plain list of findings.
- Chimney WaterproofingA breathable repellent soaked into sound, repaired chimney brick so it takes up less rain and still dries out.
Background reading
- 6 minSalt Air, Wind and Coastal Chimneys: What the South Coast Does to Masonry and MetalWind off the water drives rain into masonry and salt into metal. What that means for caps, flashing, crowns and mortar near the coast.
- 6 minBefore You Light a Wood Stove This Winter: A ChecklistThe flue, the wood, the clearances and the permit: what to check before the first stove fire of the season, or before installing a new one.
- MapThe four places we coverNew Bedford · Dartmouth · Fairhaven · Acushnet, all from one office downtown.