When water begins leaking from the ceiling or fireplace, most homeowners are primarily concerned with how it will affect the interior of their home. What many fail to realize, however, is that the same leaks that cause unsightly staining on walls can also do permanent damage to a chimney system.
Water entry into a home or chimney can be caused by a number of different issues, but is almost always indicative of a serious problem that should be assessed by a professional immediately. It is often recommended that no internal repairs, such as replacing or repainting drywall, are completed until the root cause of the leak is identified and repaired.
What causes leaky chimneys?
Chimney leaks can be caused by a variety of problems, all of which should be evaluated and repaired by a professional. Long term exposure to moisture can cause rusting of metal parts and pieces, rotting of adjacent wood, and permanent damage to the masonry or brick work.
One of the most common causes for chimney leakage is an uncovered chimney. With nothing to shield the chimney and flue, rain water, hail, sleet, and snow are all able to freely fall into them. Similarly, cracks can form over time around chimney crowns, causing small leaks that will continue to get worse over time.
Damaged or insufficient chimney flashing, or the sealant between the bricks or masonry of the chimney with the roof, is another common culprit for leaking. Even properly installed flashing can deteriorate over time, especially due to its high exposure to the elements. The basic brick and mortar are equally exposed to the elements; over time, even trace amounts of moisture can cause damage to a chimney during the freezing and thawing process, creating bigger cracks and allowing even more moisture penetration.
What repairs are available?
For homes where water flowing into the chimney is an issue, a crown replacement can easily be made. In addition to keeping water from entering the chimney, a properly fitted crown will also keep debris and wildlife from entering and potentially blocking the chimney. Existing minimally damaged crowns can also usually be patched and sealed, preventing further water damage.
Damaged flashing should be repaired or replaced as soon as possible, as water can damage not just the chimney but also the roof, framing, and ceiling below. Even expertly installed flashing can lose its effectiveness over time, and should therefore be checked during regularly scheduled maintenance to prevent any major leaks from developing.
While bricks are inherently porous and meant to absorb a certain amount of rain, damaged stonework can weaken the structure of the overall chimney. Specially designed waterproof or water repellent sealants can be applied to existing stonework to prevent water damage without preventing gas from passing through. Chimneys with extensive damage to the mortar or bricks may need to be significantly patched and in some cases replaced.
As always, the best way to prevent damage that can lead to costly repairs is through annual preventative maintenance. According to the National Fire Prevention Association, “Chimneys, fireplaces, and vents shall be inspected at least once a year for soundness, freedom from deposits, and correct clearances. Cleaning, maintenance, and repairs shall be done if necessary.” An annual chimney inspection by a certified technician or company such as Coopertown Services will allow for small cracks or deformities to be quickly repaired before they become major problems.