One of the most devastating things that can happen to your chimney is a water leak. Masonry is made up various materials, all of which are adversely affected by water. The way the chimney is designed protects it from the damaging effects of water, from the top down. The cap, crown, and flashing help protect the chimney from water penetration, but they must be in good shape to do the job.
A Faulty Cap
The chimney cap is installed at the top of the flue. It features a metal mesh that keeps animals and debris out of the chimney, but also helps water run off and away from the flue opening, as well as deflects wind. When a cap becomes damaged over time or is dislodged by high winds or animal tampering, it can allow water to flow directly into the chimney flue. Once water penetrates the system, all kinds of damage can occur.
A Worn Out Crown
A mortar crown should be designed to certain specifications. A good one has a slant away from the flue, is at least 4 inches at its thinnest, and has an overhang of at least 2 inches. A poorly constructed crown may be thrown together from leftover mortar. When your chimney crown was constructed or installed improperly, it will sustain damage quicker than a well-made one. Even a well-made one can crack under the pressure of sun exposure and temperature fluctuations. Water will collect in these cracks and move further and further into the system. If the cracks are allowed to remain during winter, the freeze/thaw effect will cause faster damage to the crown, resulting in chimney leak and structural damage.
Chimney flashing is made up of multiple thin sheets of metal layered specifically to prevent water penetration. Flashing is used to protect the vulnerable area where the chimney intersects with the roof. It takes an experienced technician to install the flashing correctly, taking the slant and roofing material into account. Hiring an amateur or handyman to do the job is almost a guarantee that you’ll have a flashing problem. In fact, we’re so sure that most chimney leaks start with the flashing, that it’s the first thing we check!
Even if your cap, crown, and flashing is in good shape, you still may experience a chimney leak. Your masonry may take on water over time, but this can be prevented by applying a waterproofing solution to the chimney exterior. At Anderson’s Chimney and Masonry Services, we offer waterproofing year-round. It will protect your masonry from water while allowing it to work properly, venting heat and gas, and will not change the look of your masonry at all.
Call us today at 717-975-3526 or request an appointment online.