Chimney Cap vs Chase Cover vs Crown: What's the Difference?

Chimney Cap: The Flue Cover

A chimney cap is a metal cover that sits over the flue opening — the hole where smoke exits. It has a solid top with mesh screening on the sides.

What it does: Keeps rain, snow, animals, and debris out of the flue while allowing smoke to exit. The mesh screening also acts as a spark arrestor.

Materials: Stainless steel (best value, rust-proof, lifetime warranty), copper (premium, beautiful patina), galvanized steel (budget, rusts in 5–10 years).

Cost in Chicago: $150–$700 installed depending on material and size.

Chase Cover: The Chimney Top Pan

A chase cover is a flat metal pan that covers the entire top of a chimney chase. Chase covers are found on prefabricated (factory-built) fireplaces — the kind with wood or siding on the outside instead of brick.

What it does: Seals the top of the chase enclosure to prevent water from entering. A chimney cap then sits on top of the chase cover over the flue pipe.

Materials: Stainless steel (recommended) or copper. Many builder-grade chase covers are galvanized steel that rusts within 10–15 years — the telltale sign is rust stains running down your chimney siding.

Cost in Chicago: $300–$800 for stainless steel replacement.

Chimney Crown: The Concrete Cap

A chimney crown is the concrete or mortar slab on top of a masonry chimney (brick chimney). It surrounds the flue tiles and sheds water away from the chimney structure.

What it does: Prevents water from entering the chimney between the flue and the outer brick walls. It should have a 2-inch overhang with a drip edge.

Materials: Concrete or specialized crown mix. NOT regular mortar (though many builders use mortar, which fails much faster).

Cost in Chicago: $400–$1,500 for repair or replacement.

Which One Do You Need?

Masonry chimney (brick): You have a crown and need a cap. No chase cover.

Prefab chimney (sided): You have a chase cover and need a cap. No crown.

Many prefab chimneys need both a new chase cover AND a new cap — especially if the original galvanized chase cover has rusted.

Not sure what type you have? A quick chimney inspection will tell you exactly what components you have and their condition.

Not Sure If Your Chimney Is Safe?

Take our free 2-minute safety checklist. 15 warning signs every Chicago homeowner should check — with an instant risk score.

Need Professional Help?

Widen Chicago provides honest diagnostics, transparent pricing, and expert service for every chimney and vent job. Same-week scheduling available.