The weather gradually erodes the crown of the chimney from the top-down, resulting in a deteriorated chimney. Water, sun, and freezing and thawing gradually erode the crown, causing cracks to form. Those living in cold climates who frequently have warm days that are followed by cold snaps (such as we experienced over the winter) are particularly vulnerable to the water damage caused by freezing. In this article we will discuss some possible ways recommended by atlantic brick & stone mason to protect and maintain chimney crown from these damages.
A Chimney Crown
The cracking process accelerates as soon as they appear. The cracks allow water to circulate, eventually causing the bricks underneath to deteriorate. Your house can sometimes become infected with it. When masonry can degrade to the point that it is loose or even falls off the chimney, it exposes nearby people and animals to masonry falling on them. When a wash is repaired before it gets too out of hand, it is less costly than when a chimney is restored after significant decay has occurred. The level of protection you want for your chimney, as well as your budget, can determine the options you have. The term “crown” (sometimes called a wash) refers to a covering of concrete or mortar applied to the top of your chimney to transfer water away from your flue and onto the roof.
A crown sealant can possibly protect against water absorption by the crown. It is a plasticized coating applied to the crown. Typically, it lasts for about ten years, and then it has to be renewed. The cost of crown sealants usually does not exceed a few hundred dollars, and they protect your chimney crown for about ten years. Crowns that are badly damaged cannot be sealed with sealant. Usually, a new crown is made by removing the old cement from the old crown and making it from scratch again. Sealant, however, is only designed to protect the top of the chimney. When your flue has no protective cap, it’s open to both critters and the elements. Kritters are a nuisance, but if the flue tiles deteriorate significantly, they may cause the chimney to require relining.
Flue Caps
You can install a flue cap over the top of your flue to keep out snow, rain, and animals (birds’ nests are difficult to remove without destroying the nest, and raccoons are difficult to remove without causing damage to everyone involved). For the least expensive method of protecting your flues, stainless steel caps with lifetime warranties usually cost less than $250.
For both protection of your chimney crown and protection of your flue/s, the best option is a full-coverage, multi-flue chimney cap, which extends beyond the edge of the chimney crown to protect it from the elements and substantially reduce your maintenance costs. All of these caps are available in either stainless steel (which can be powder coated in many different colors) or copper, with a lifetime warranty. There are painted steel chimney caps that are cheaper, but they are not as sturdy as stainless steel. Caps usually cost $400 to $600, depending on the chimney’s size.