The most weather-beaten parts of your chimney are the ones you never see: the cap and the crown at the very top. They take the full force of rain, snow, and wind year-round, and when they fail, the damage travels straight down into the structure. For homeowners in Plainfield, these two components are the first line of defense for the whole chimney.
The difference between a cap and a crown
People often use the terms interchangeably, but they do different jobs. The crown is the sloped concrete or masonry surface that caps the top of the chimney around the flue opening; its slope is designed to shed water away from the brick. The cap is the metal cover — usually with mesh sides — that sits over the flue itself. Together they keep water, animals, and debris out while letting smoke escape. When either one fails, the chimney loses that protection.
What a missing or damaged cap lets in
An open or broken cap is an invitation to trouble. Rain falls directly down the flue, speeding up rust and moisture damage inside. Birds and small animals move in, building nests that block the flue and create a genuine fire hazard. Leaves and twigs collect and restrict airflow. And on a windy day, an uncapped flue is more prone to downdrafts that push smoke back into your living room. A simple cap prevents all of it.
Keeping the crown sound
The crown lives a hard life, and small cracks are common as it ages. Left alone, those cracks let water seep into the chimney and freeze, widening the gap each winter. Catching a crown problem early often means a straightforward sealing rather than a full rebuild. Our chimney cap and crown service covers inspection, sealing, and replacement so the top of your chimney keeps doing its job.
A sound cap and crown quietly prevent some of the costliest chimney repairs there are. Call Indigo Chimney Sweep at (815) 296-9565 or book online to have yours checked in Plainfield. We are bonded and insured.
Frequently asked questions
What is the difference between a chimney cap and a crown?
The cap is the metal cover with mesh sides that sits over the flue opening. The crown is the sloped masonry or concrete surface that covers the top of the chimney around the flue. The cap keeps things out of the flue; the crown sheds water off the structure.
Do I really need a chimney cap?
In almost every case, yes. Without one, rain falls straight down the flue, animals and birds can nest inside, and burning embers can escape onto the roof. A cap is an inexpensive part that prevents several expensive problems.
What animals get into an uncapped chimney?
Birds, squirrels, raccoons, and bats are the usual visitors. Beyond the mess and odor, nests are a serious fire hazard and can block the flue, causing smoke or dangerous gases to back up into the home.
Can a chimney cap stop downdrafts?
A cap will not cure every draft problem, but certain cap designs help reduce wind-driven downdrafts that push smoke back into the room. If downdraft is a persistent issue, an inspection can pinpoint the cause.
How do I know if my crown is damaged?
Look for cracks, crumbling edges, or pieces of concrete on the roof or in the gutters. A damaged crown may also show up indirectly as leaks or damp spots, since a cracked crown lets water pour into the chimney.
Can a cracked crown be repaired, or must it be rebuilt?
Small cracks can often be sealed with a specialized crown coating, while a severely deteriorated crown needs to be rebuilt. An inspection determines which is appropriate for your chimney.
Are stainless steel caps worth it?
Generally yes. Stainless resists rust far better than galvanized steel and typically carries a longer service life, which makes it a sound choice for our climate.
How often should the cap and crown be checked?
At each annual inspection. Both are exposed to the harshest weather of any chimney component, so a yearly look ensures small cracks or a loose cap are caught before they let water in.
Written by Jamie Reed, operations manager at Indigo Chimney Sweep.
Published August 31, 2026