Chimney crowns and caps
The top of the chimney takes the worst of the weather. A sound crown and a good cap protect everything below them.
The crown is the concrete or mortar slab that covers the top of a masonry chimney around the flue. The cap is the metal cover with mesh sides that sits over the flue opening. Together they decide how much water, snow and debris ends up inside your chimney.
Why do crowns crack?
Many older crowns were made from a thin wash of leftover mortar, sloped just enough to shed water in theory. They shrink, crack and absorb water. In a climate with as many freezing days as Duluth, that water freezes in the cracks every winter and widens them. Once the crown is open, water runs down inside the chimney and into the brick from the top.
Repair or replace?
- Hairline cracks on an otherwise sound crown can often be sealed with a crown coating made for the purpose.
- Wide cracks, crumbling or missing pieces usually mean a new crown.
- A well-built replacement is thicker, slopes away from the flue, overhangs the brick with a drip edge so water falls clear of the face, and leaves a small gap around the flue tile so the two can expand separately.
Why does a chimney need a cap?
- Keeps rain and snow from falling straight down the flue
- Keeps birds, squirrels and raccoons out
- The mesh acts as a spark arrestor for wood-burning fireplaces and stoves
- Can reduce downdrafts on windy lakeside and hilltop lots
Stainless steel or copper caps hold up better than galvanized ones, which can rust through. A multi-flue chimney may need a single cap that covers the whole top. On a chimney serving a gas or oil appliance, the cap should be the type the appliance and liner maker allow.
What affects the price?
- Crown sealing versus full replacement
- Chimney size and number of flues
- Cap material and whether it's custom-sized
- Roof pitch, height and access
The chimney company prices the job after seeing the chimney, usually from the roof and inside the flue. We don't quote prices, and any figure given over the phone before an inspection is only a rough starting point.
Where we connect you with help
Common questions
Is a cracked chimney crown urgent?
It's worth fixing before winter. Cracks let water into the top of the chimney, and freezing widens them each season, so a small repair now can prevent masonry damage later.
Can ice dams or heavy snow damage a chimney cap?
Heavy snow and ice can bend or loosen cheap caps. A sturdy, properly fastened cap holds up better. Have it checked if it's tilted or missing after a storm.
Related services
- Chimney masonry and tuckpointing
- Chimney liners and relining
- Chimney leak repair
- Chimney inspection and sweeping
More background: Duluth chimney guide.
Loose brick, a leaking chimney or a stove you haven't had checked?
Call now and a local chimney company will look at it and quote the work.