How long does a chimney crown last?
There is no fixed number of years. A crown that was built thick, sloped and overhanging, and sealed when the first cracks showed, can last a long time. A thin one left alone can fail much sooner. What matters is how it was made, the weather it faces and how early you catch cracks.
What does a crown do?
The crown is the slab across the top of a brick chimney. It slopes away from the flue so rain runs off instead of soaking into the brick and mortar below. When it cracks, water has a way into the whole stack.
What makes one crown outlast another?
- How it was built. A crown shaped from a proper mix, with a slope and an overhang, sheds water. A flat skim of mortar holds water.
- Freezing weather. Water in a crack freezes and widens it, then repeats. Minnesota winters give a small crack plenty of chances to grow.
- The cap above it. A cap keeps rain off the flue opening, and a good crown overhang keeps water off the brick.
- Early sealing. A hairline crack coated early is cheaper to deal with than a wide one left for years.
What can you check from the ground?
Stand back and use binoculars or the zoom on your phone. Look for white or dark streaks running down the brick below the crown, bits of crown on the ground and any visible cracks. Stay off the roof and the ladder for this. We do the close look.
| Sign | What it means | Next step |
|---|---|---|
| Hairline cracks | Early wear | Have it looked at, likely a seal |
| Wide cracks or gaps | Water is getting in | Call, likely a rebuild |
| Crumbling surface | The material is failing | Call, likely a rebuild |
| Streaks below the crown | Water running down the brick | Book a look soon |
What does a crown repair involve?
For hairline cracks, we clean the surface and coat it with a sealer made for masonry crowns. For wide cracks or a crumbling slab, we break out the old crown and pour a new one with a slope and an overhang. We show you the cracks first and explain which road fits yours.
When to stop and call
Call if a piece of the crown has fallen, if the crown has cracked through, or if water stains show near the chimney inside the house. Do not climb up to patch it yourself, and keep people clear of the base if pieces are dropping. Our caps and crowns service covers sealing, rebuilding and new caps. We look at crowns in Oak Park Heights, St. Paul Park and across the east metro.
Crown questions
Short answers first.
Is a hairline crack in the crown a problem?
It is an early warning. A small crack lets in a little water, and freezing widens it. Sealing it while it is small is the simple fix.
Can I seal a crown crack myself?
Crown work is on the roof, and a sealer only holds on a sound, clean surface. We would rather you stay on the ground. A call is enough to start.
Does a cap protect the crown?
It helps, because it keeps rain off the flue opening. The crown still needs to slope and overhang to shed water from the brick.
Cracks at the top of your chimney?
Describe what you see from the ground, and we will tell you what it likely needs.