Keep an Eye on Your Chimney Crown

Chimney crowns are concrete slabs that cover the entire top of a masonry chimney minus the flue opening. Because of their location, they’re never seen unless someone is up on the roof.

But your chimney crown performs a very important job, so it’s in your best interests to inspect it yourself or schedule an annual chimney inspection that will include an assessment of the chimney crown.

Mercer County Chimney Services of Hamilton, NJ, would like to share a little about what crowns are, what they do and why you should keep an eye on yours.

Chimney crown structure

As noted, a chimney crown is made of concrete and covers the top of a chimney around the flue pipe. When built correctly, it will be angled downward on all sides to encourage water and snow to run off it.

A crown should also have a bit of an overhang, or drip edge, which helps to keep water from running down the chimney’s bricks.

What a chimney crown does

The primary purpose of a chimney crown is to prevent water and debris from getting into interior areas of the chimney system. Rainwater and snow are the biggest concerns.

Water intrusion through a crown with significant cracks or major deterioration can lead to:

• Cracking and spalling (flaking) of chimney bricks
• Crumbling masonry mortar joints
• Rotting of adjacent building materials of the home
• Rust on the fireplace damper
• Damage to sections of the firebox
• Mold growth that can spread throughout the home

How to tell if your chimney crown needs service

If you’re comfortable getting up on your roof, you can take a close look at your chimney crown from all angles. If you’re not comfortable, let a chimney technician do it.

See if there are any cracks in the concrete. In more severe cases, you might notice deteriorated concrete that leaves large holes in the crown.

Watch for common signs of a chimney leak that may point to an issue with the crown:

• Water in the firebox
• Musty smells coming from the fireplace
• Damp sections of walls or ceilings near the chimney
• A squeaky damper that’s hard to operate

Spotting damage in a chimney crown isn’t hard. The difficult part is simply remembering to get up there and check it periodically.

Addressing crown damage

Chimney companies have several options in addressing damage to a chimney crown.

Seal the crown

 A waterproof sealant is applied across the crown to keep water from getting into existing cracks. Note that the sealant does not repair cracks or prevent new ones.

Patch the crown

 Larger breaks in the crown structure can sometimes be patched with a special compound designed for this purpose. If the problem stems from the crown’s age or was caused by inferior materials used to build it, patching is more of a “Band-Aid on the wound” than a long-term solution.

Rebuild the crown

 Chimney crowns with major damage from ongoing water intrusion, lightning, hail, a chimney fire, falling trees or old age usually need to be rebuilt. This way, you end up with a nice strong crown that’s built correctly and will reliably serve you and your chimney for many years.

Get your chimney into top shape

Mercer County Chimney Services is here to help with your chimney crown issues. We provide all types of chimney repairs, chimney sweeping and licensed chimney inspections. Call us first in Mercer County, NJ, or reach out by using our contact form.