If the chimney on your home is covered in siding instead of brick, it is not a chimney in the traditional sense. It is a framed box, called a chase, with a metal pipe inside, and it fails in its own particular way. AM Chimney Sweep replaces chase covers and services factory-built fireplaces in Bedminster, along with cleaning and inspection.
Why this is the Bedminster chimney
Census Bureau estimates show that nearly six in ten Bedminster homes were built in the 1980s, and about four in ten are attached homes such as townhouses. Housing of that type and period was very often built with factory-built fireplaces, not masonry ones. If yours dates from then and the chase cover has never been replaced, that sheet-metal cover is now around forty years old.
Source: U.S. Census Bureau, American Community Survey 2020–2024 five-year estimates.
How a factory-built fireplace is put together
- Firebox. A steel box lined with cast refractory panels that look like brick.
- Chimney pipe. Insulated or air-cooled metal pipe, made by the same manufacturer as the firebox and tested with it as one system.
- Chase. The wood-framed enclosure around the pipe, finished to match the house.
- Chase cover. A sheet-metal pan that closes the top of the chase, with a hole for the pipe.
- Storm collar and cap. The collar sheds water where the pipe passes through the cover; the cap finishes the top of the pipe.
The part that fails first
Builders generally fitted galvanized steel chase covers, and many were made flat. Water collects in the middle, the zinc coating wears through, and the steel rusts. Eventually pinholes open, or the seam around the pipe gives way.
What you see
- Rust-colored streaks running down the siding beneath the chimney top
- A cover that visibly sags or holds a puddle
- Water stains on the ceiling or wall near the fireplace
- Rust inside the firebox or on the damper
- Soft or discolored trim at the top of the chase
- A musty smell from the fireplace in damp weather
What is happening out of sight
Water entering through the cover runs down inside the chase. It soaks the wood framing, which rots; it rusts the outside of the chimney pipe and the top of the firebox; and it can travel into the wall and ceiling beside the fireplace before any stain shows. The longer it runs, the more of that has to be repaired as well.
What a proper replacement looks like
- Stainless steel, which does not rust through
- Made to measure for your chase, not a stock size bent to fit
- Cross-broken, meaning creased from corner to corner so the top sheds water instead of holding it
- A raised collar around the pipe opening, so water cannot run into the hole
- Side skirts with a drip edge that carry water clear of the siding
- A new storm collar, sealed, and the cap refitted or replaced
Our process is described on the chimney caps and chase covers page.
Inside the firebox
The refractory panels crack with heating and cooling. Fine hairline cracks are normal. Panels should be replaced when cracks have opened wide, pieces are missing, or the surface is crumbling, because the panels are what protect the steel behind them. Replacements need to be the correct ones for the unit.
Rules that are specific to factory-built units
- Parts are not interchangeable between brands. The pipe, cap and firebox are listed together, and substitutes can create a fire hazard.
- These fireplaces are built for moderate fires. Do not overload them or burn them like a masonry fireplace.
- Never install a wood stove or insert into one unless the manufacturer specifically permits it.
- The metal chimney still collects creosote and still needs cleaning and a yearly inspection.
If you live in a townhome or condominium
Responsibility for the chase and its cover varies from one association to another. In some it belongs to the owner, in others to the association as part of the exterior. Check your governing documents or ask the management office before arranging work, and find out whether there are rules on materials or appearance. We are glad to provide a written report and estimate that you can pass to the association.
Schedule service in Bedminster
Call (862) 225-6529 or send a request online. To see a finished job of this kind, read our chase cover installation in Monroe Township, or browse Our Work.