People often use “cap” and “crown” interchangeably, but they’re two different parts of your chimney — and both are essential for keeping water out. Here’s the difference.
What is a chimney crown?
The crown is the sloped concrete or mortar slab at the very top of the masonry chimney. It covers the entire top surface (except the flue opening) and is built to shed rain away from the brickwork below. A cracked crown is one of the most common causes of chimney leaks.
What is a chimney cap?
The cap is the metal cover — usually stainless steel — that sits over the flue opening itself. It keeps rain, animals, leaves and sparks out of the flue while still letting smoke draft out, thanks to its mesh sides.
Why you need both
Think of it this way: the crown protects the top of the masonry, and the cap protects the opening of the flue. A chimney with a good crown but no cap still lets rain and animals into the flue; a cap without a sound crown still lets water into the brickwork. Together, they keep the whole chimney dry.
| Chimney Crown | Chimney Cap | |
|---|---|---|
| What it is | Concrete/mortar slab on top | Metal cover over the flue |
| Main job | Sheds water off the masonry | Blocks rain, animals & sparks |
| Common problem | Cracking, letting water in | Rusting, blowing off, or missing |
How to tell one needs attention
- Crown: visible cracks, crumbling edges, or water stains inside
- Cap: rust, a bent or missing cap, or animals/debris in the flue
Need a cap or crown checked?
We inspect, repair and install both to keep water out of your chimney.