What is a Chimney Crown & Should I be Concerned if It is Cracked?
A chimney is a little more intricate than it appears. There are several elements that must be in good working order for the chimney to filter smoke and gasses to the outside of the house and to keep water out of the structure. The chimney crown is an often-overlooked part of a chimney, but it’s one you need to be aware of.
These important devices are much more than decoration for the top of a chimney. Commonly made of concrete, chimney crowns are designed for protection. You can imagine what kind of trouble could arise if you had a chimney with nothing on top of it. Before long it would be letting in water, which will damage a chimney.
Concrete is a better material for chimney crowns than masonry, which deteriorates fairly quickly when exposed to rain water. Protecting the top of the chimney around the flue is of critical importance, because if water gets into the system, serious problems will arise including cracking and breaking of the masonry within the chimney. This can allow intense heat to escape the structure and cause a fire in adjacent materials.
A good crown will have a slightly down-angled design, which lets water runoff it and away from the chimney. The design should include an overhang that extends a few inches beyond the chimney. A flat crown would retain rain water and water from melting snow.
Chimney crown damage
Often damage to the crown goes unnoticed, because it’s in an area of the structure homeowners never see unless there’s a reason to get up there and inspect. Even the best-made crowns will suffer from exposure to the elements, temperature fluctuations and direct sunlight over time. For this reason, homeowners should either make regular inspections or hire a professional, who can inspect the crown along with other annual cleaning and maintenance tasks.
If you find very small cracks in the crown, a good waterproof sealant can repair them and prevent further expansion. For more serious deterioration, it’s wise to consult with an experienced chimney sweep to determine if repairs can be made to the existing crown of if a new one should be constructed.
In some areas, chimney crowns can support the growth of moss and algae. The trouble here is that this growth holds water and prevents runoff, which is exactly what you don’t want. Ask your hearth retailer for a good chemical solution to remove moss and algae. You can do this job yourself, just be careful on the roof.
As noted, the only way to determine if your chimney crown needs significant repair or rebuilding is to actually get up there and look at it. Under no circumstances should you attempt repairs that you are unsure about, because you may end up causing far more damage than you started with.
Hudson Valley Chimney has served the greater Poughkeepsie, N.Y., area since 1976 with professional chimney sweep, chimney inspection and complete chimney repair services. If you suspect there’s a problem with your chimney crown, we can assess the situation and provide the specific service you need to be able to run your fireplace with peace of mind. Call us at (845) 471-1071.