Your chimney crown is the ceiling that covers the top of the chimney opening. It endures abuse from weather and critters on the outside and heat from the inside. Over time the crown can become damaged–especially if it isn’t constructed or maintained properly.
The Chimney Crown
This slab of concrete extends from the flue pipe to the edge of the chimney at a slant so that water runs off. The crown should have a two-inch overhang so that water drips off instead of running down the masonry, staining and damaging as it goes. It should be constructed of concrete and reinforced with steel mesh. Because water, ice, and snow are hard on the crown, it should be at least 4 inches thick at its thinnest point. When chimney crowns are not constructed to these specifications they do not last as long and end up allowing water into the chimney system, causing water damage.
Incorrectly Constructed Crowns
Cutting corners with the crown is not a good idea. While some chimney sweeps choose to construct the crown from leftover mortar, this is not recommended. A mortar crown will not stand against water and weather abuse and will need to be repaired or replaced often to avoid costly damages. Forming a flat crown is definitely easier, and if your technician replaces your crown with a flat substitute, he or she is most likely an amateur and not a trained and certified chimney sweep. Similarly, if the crown doesn’t have an overhang, it is constructed incorrectly and will lead to staining and water damage on the masonry itself, and may leak through the flashing at the base of the chimney.
Chimney Crown Repair
There may be points in time that your crown needs attention. Problems with the crown may be discovered during a routine chimney inspection or as a result of damages. If cracks, voids, and deterioration are discovered during an inspection, but the overall structure is okay, it can be an easy fix. Black Moose technicians are experienced and certified to apply an industrial product that seals the crown and prolongs its life. If, however, the crown is badly damaged or constructed incorrectly, we can replace it quickly and correctly. Our certified chimney sweeps construct chimney crowns from the correct materials, with the right shape and overhang for it to work properly. We can then apply a waterproof sealant to the entire exterior portion of the chimney to prevent water penetration and damage.
Schedule Chimney Maintenance Now
When you schedule your chimney sweep and inspection annually, you’re less likely to experience issues with your chimney system. Do not light a fire in a chimney that hasn’t been inspected in the last 12 months, especially if your area experiences strong winds, earthquakes, and storms that can affect parts of your chimney system (like the crown). Even one season of cold weather can badly damage a chimney system if water is allowed into the system. Avoid this costly damage, decreased chimney efficiency, and danger of fire by scheduling routine maintenance now.
Call Black Moose Chimney and Stove now at 603.525.7905. You can also request an appointment online.