What is a chimney chase and a chase cover?
A chimney chase is the boxed-in frame — usually wood-framed and sided to match the house — that hides the metal flue of a factory-built (prefab) fireplace, standing in for a masonry chimney. The chase cover is the metal lid on top of that box, sloped to shed water around the pipe where it exits. Together they weatherproof a prefab chimney.
The prefab stand-in for masonry
Not every fireplace has a brick chimney. Factory-built (zero-clearance) fireplaces vent through metal pipe, and builders enclose that pipe in a chase — a framed, sided box running up the outside of the house or up through it — so from the curb it reads like a normal chimney.
Inside, it's just the metal flue and its clearances. Most homes built in the last few decades around WNC use this approach rather than full masonry.
Chase cover versus chimney cap
People mix these up. The chase cover is the flat, sloped metal top that closes off the whole box, with holes for the flue pipes to pass through; its job is to keep water out of the chase.
The chimney cap is the smaller screened lid that sits over the actual flue opening on top of that. You typically have both — the cover seals the box, the cap protects the flue.
Where they fail — and why it matters
Chase covers are the usual culprit in prefab chimney leaks. A thin galvanized cover rusts, or it was built flat instead of sloped so water pools and finds the seams, and suddenly you've got staining and rot inside the chase.
We swap failing covers for stainless with a proper slope and sealed collars. If you've got a boxed chimney with rust streaks down the siding, that's the tell — call (828) 545-0525 and we'll inspect it.
How we can help
Related questions
- What does a chimney cap actually do?
- What is a chimney crown, and how is it different from a chimney cap or chase cover?
- What's the difference between a masonry fireplace and a prefab factory-built fireplace?
- What is a zero-clearance fireplace?
- What is a flue?
- What is a direct vent gas fireplace and how does it work?
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