Before you order a chimney cap or a chase cover, you need to know which type of chimney you actually have. The answer determines what you need — and ordering the wrong product leaves part of your chimney completely unprotected. This is one of the most common and most preventable mistakes homeowners make.
Here's how to tell the difference, what each chimney type needs, and why a chimney cap is not a substitute for a chase cover on a wood-framed chase.
How to Tell Which Chimney You Have
Walk outside and look at your chimney from the ground.
If you see stacked brick or stone all the way up — solid masonry from the roofline to the top — you have a traditional masonry chimney. At the very top is a concrete or mortar slab called the chimney crown, with one or more clay flue tiles poking through it.
If your chimney looks like a box — sided with vinyl, wood, stucco, or fiber cement to match the house — you have a wood-framed chimney chase. Inside that box is a metal flue pipe. The top of that box is open framing that needs a flat metal cover to seal it.
Most homes built before the 1980s have masonry chimneys. Most homes built or renovated since then — and virtually all prefab fireplace installations — have wood-framed chases. If you're not sure, text a photo of your chimney to (609) 352-9840 and we'll tell you exactly what you have.
Masonry Chimneys: What They Need
A traditional masonry chimney is built from brick or stone all the way up. The chimney crown — the concrete slab at the top — is the surface a cap sits on. It surrounds the flue tile and is structural, solid, and part of the chimney itself.
For a masonry chimney, a custom chimney cap — also called a chimney topper, chimney rain cap, or chimney cover — spans the full width of the chimney top and acts as a standing-seam metal roof for the chimney. It sits on the crown, covers the flue tile openings, and protects the crown from direct weather exposure. Rain rarely touches the crown. Freeze-thaw cycles can't crack what they can't reach.
A masonry chimney does not need a chase cover. The crown is the chase cover equivalent — it's concrete, it's built in, and it's already there.
What it does need is a cap that covers the entire chimney top — not a standard single-flue cap that only covers the flue tile opening and leaves the crown exposed. That distinction matters. Read more about chimney crowns and why they crack →
Wood-Framed Chases: What They Actually Are
A wood-framed chimney chase is a framed enclosure — built from lumber and sheathing, finished with siding — that surrounds a factory-installed metal flue pipe. It's not a chimney in the masonry sense. It's a box built to house and hide the pipe.
The top of that box is open framing. It has no concrete crown. It has no structural top. Without a flat metal cover — a chase cover — the top of the chase is completely open to rain, snow, and debris. Water enters, soaks into the wood framing, and causes rot, mold, and structural damage from the inside out. By the time rust stains appear on the siding, water has usually been getting into the framing for at least a season.
The chase cover — also called a chimney pan or chase pan — is the flat metal piece that seals the top of the chase. It lays across the entire top of the framing, with the flue pipe passing through a collar in the center. It's sloped for drainage, hemmed at the edges, and on a properly fabricated cover, the flue collar is soldered — not just cut and folded.
What a Chase Cover Is — And What It Isn't
A chase cover is not a chimney cap. A chimney cap is not a chase cover. They protect different things and they are not interchangeable.
A chase cover seals the top of the wood-framed chase — the entire flat surface of the framing. It has a hole (or multiple holes) for the flue pipe to pass through. It lays flat. It protects the wood.
A chimney cap sits on top of the chase cover, over the flue pipe opening. It has an open bottom with a spark screen. It keeps rain, animals, and debris out of the flue. It does not have a flat bottom with pre-cut holes for the flue pipe. It does not seal the top of the chase.
If you put a chimney cap on a wood-framed chase without a chase cover underneath it, the cap covers the flue opening — and nothing else. The rest of the chase top remains completely exposed. Rain hits the framing directly. The cap gives you the appearance of a protected chimney while the wood underneath it rots.
On a wood-framed chase, you need both. The chase cover goes on first. The cap mounts on top of it.
One thing worth knowing: a side mount cap — with a vertical skirt that wraps down around the outside of the chase cover perimeter — will hide the chase cover completely. From the ground, you see the cap. The stainless steel surface of the cover underneath is tucked behind the skirt. If aesthetics matter and you don't want bare stainless visible on the chimney top, a side mount cap solves that automatically.
Why the Chase Cover Material Matters
Builder-installed chase covers are almost always galvanized steel. Builders use them because they're cheap. The problem is the galvanized coating fails — typically within 5 to 10 years — starting at the seams and fastener points where the coating gets scratched during installation. Once rust starts, it spreads. You'll see orange-brown stains running down the chimney siding before you realize the cover itself has failed. By then, water has been getting into the framing.
Stainless steel is the right material for a chase cover. We use 2B 304 24 gauge — the same spec used in commercial and architectural applications. It doesn't rust. It handles coastal environments, salt air, and freeze-thaw cycles without issue. It will outlast the framing it's protecting.
Copper is the premium option — the same corrosion resistance as stainless, with a patina that develops over time. If your home has copper roofing details or you're building to last indefinitely, copper is worth it.
We also build in Kynar-finish aluminum and Galvalume for budget-conscious applications. Whatever the material, every flue penetration gets a 3" soldered waterproof standing collar — standard, not an upcharge. Most fabricators treat soldering as optional. We don't.
How to Order
For a chase cover, we need the outside dimensions of the chase top — full length and width — and the outside diameter or dimensions of your flue pipe. We cut the flue collar to your exact dimensions and solder the collar as standard. Download the chase cover measuring guide →
For a chimney cap to go on top, check our chimney cap measuring guide → or text a photo of your chimney to (609) 352-9840 and we'll walk you through both pieces before you order anything.
Lead time is 3–4 weeks. Every order ships anywhere in the USA in a custom wood crate via insured LTL freight.
Browse custom chimney chase covers → — hand-fabricated to your exact dimensions. Ships anywhere in the USA.
Browse our custom chimney caps → — custom fabricated to cover your entire chimney top. Ships anywhere in the USA.
Sean has 32 years of experience fabricating and installing sheet metal components, copper roofing, and custom architectural metalwork — including historic preservation projects on schools, churches, and government buildings. Every cap and cover that ships from Archaic Metal is built by hand in New Jersey.