Of all the things that keep your chimney working properly and lasting a lifetime, the parts that protect it against water is the most vital part. The very material that makes the chimney ideal for fireplace ventilation is also extremely susceptible to water penetration and damage. The only way to protect your chimney against water over the life of your home is to make sure the cap, crown, flashing, and masonry are professionally installed. Of all the parts, the crown can take on substantial damage when constructed improperly.
All About the Crown
Your chimney crown acts as a ceiling for your chimney. It should be constructed specifically to shed water away from the flue and masonry. In this image provided by the CSIA, the flue pipe rises up from the middle of the chimney structure and the crown covers the top. What is not pictured is the cap, which protects the flue opening and the crown. A thin, flat crown will take on damage no matter what material it is made of. However, a crown that is shaped properly can become damaged quickly if it isn’t made from quality materials. A well-constructed crown should consists of the following:
- Chimney crowns should be constructed of concrete—not mortar—and reinforced with wire mesh.
- The chimney crown should be 4 inches thick at a minimum with a slight slope to shed water off the crown.
- The crown should cover the chimney from the flue opening and extend at least 2 inches past the chimney.
- Underneath the edge of the crown, there should be a drip edge to prevent water from running down the masonry but falling onto the flashing below.
- The concrete crown should not come into contact with the flue tile, but it needs to have a ¼ inch separation created during construction.
When your chimney system is compromised by water, your whole home can suffer. Water causes stains and damage, ceiling leaks, and more. You should only hire a professional for your comprehensive care and maintenance. An amateur cuts cost by using leftover mortar to construct the crown. If your chimney has a mortar crown, it will need maintenance more often and require regular sealants with special industrial products. They will not last over time against weather and direct sunlight either.
At Trinity Chimney Service, we specialize in crown rebuilding and replacement, crown repair, and crown waterproofing. When you choose Trinity for your crown work, you can count on a finished product that is beautiful and durable. We repair damaged crowns with CrownSeal, a product that provides 10 years of protection against leaks and seals cracks and gaps for good. If you have a poorly constructed crown, we may be able to improve it instead of replacing it completely. Call us today and schedule one of our chimney experts today. Call 443-602-4306 or request an appointment online.