Cracked Chimney Crowns Cause Many Problems


Simply stated, cracked chimney crowns cause deterioration of your chimney! Because crowns are located on top of your roof, without a professional inspection from a member of the Chimney Safety Institute of America (CSIA) you may have no way of knowing there is damage being done until it’s too late. Pozzi Chimney Sweep, located in Illinois, knows that chimney crowns are subject to the elements and the effects the four seasons take on brick and mortar.

Cracked Chimney Crown - Aurora IL - Pozzi Chimney

Chimney crowns are the umbrella to your chimney. The purpose of your chimney crown is to prevent water from seeping into your chimney, and therefore must be functioning properly to do it’s job. Cracks, deterioration of the mortar, loose bricks, and other structural problems cause leaks and problems. Temperature such as wind, cold, rain, and heat all lead to chimney problems that must be addressed by a professional. Additionally, if you live in an area with seismic activity, even minor quakes can cause damage to the chimney’s structure.

Cracked or damaged masonry can lead to moisture accumulation ideal for the growth of moss and algae. When the masonry is worn or cracked away, water seeps into the brick causing structural damage. Water damage can also cause spalling and efflorescence which also weaken the brick.

Often, all that is needed is a chimney crown sealant. Sealant works if there are just a few very minor cracks and the sealant can help keep moisture from seeping into the brick, mortar, and concrete. If sealants are used alone, they probably will not last long and serve only as a band-aid and more extensive repair work will be needed.

In most cases, when there is apparent deterioration of the existing crown, you will need to hire a skilled and experienced professional to rebuild your chimney crown. According to the WiseGeek website, “When a chimney crown is added to a home, the homeowner should make sure it is made of the right materials. Masons will sometimes build a crown that isn’t up to par, and if the homeowner doesn’t know the difference, he’ll end up paying only to watch the chimney rapidly deteriorate over the next few years. The number one rule is to never use bricks. The whole reason for a chimney crown in the first place is because mortar isn’t weatherproof, so if a mason is using mortar and bricks to construct the crown that should be a warning sign. Instead, opt for metal, stone, or concrete slabs. Pre-cast or cast in place concrete crowns that are reinforced with steel are good solutions as well. Crowns can even be made of metal or stone, as long as they are water-tight and weather resistant.”

As a reminder, “The crown should slope down from the flue liner. The angle of this slope should be a minimum of 3 inches of fall per foot of run. Flat or low slope crowns can allow water to enter the interior of the chimney. A chimney crown should extend a minimum of 2 and 1/2 inches beyond the face of the chimney on all sides. This overhang helps to keep water from running down the chimney face. The bottom of the crown should contain a small kerf (drip). Without the kerf, water can roll underneath the crown and flow down the face of the chimney”, according to Tim Carter from Ask The Builder.

Cracked crowns are just one of the many potential hazards that a trained chimney professional can look for when doing their inspections. Like everything else, catching problems early mean lower repair costs and less damage.