What is Chimney Spalling?
You’ve been admiring your chimney for years and it has been a workhorse throughout the long winters. But it’s not looking as handsome as it used to and you can’t seem to put your finger on the problem. Upon closer inspection, however, you notice that some of the bricks are broken while others seem to have completely disappeared. This is called chimney spalling and it needs to be inspected and repaired by a professional chimney specialist as soon as possible.
While it’s difficult to pinpoint the exact cause, there are a number of reasons that chimney spalling may be occurring. It could be the age of your home. That’s because spalling is more prevalent in older homes, especially those built in the 1970’s and earlier where the mortar and masonry are showing signs of wear and are deteriorating. It can also be seen in pre-fabricated homes where sub-standard components may have been used in the brick or masonry manufacturing process.
Pressure washing may be the culprit too. While many homeowners use pressure washing to clean the exterior of their homes, exuding too much force can cause spalling, especially in older masonry that is already softening. Typically, pressure washing a brick chimney should be done at a low pressure of 850 PSI or less.
Another major cause of spalling is the environment. The damaging effects of wind, rain, hail, snow and heat can wreak havoc on exterior masonry surfaces. The dramatic changes in climatic conditions can eventually pierce the protective outer layer of the brick masonry allowing water to penetrate resulting in even more and progressive damage. This is when the face of the bricks begins to resemble pieces of Swiss cheese. If the spalling is not addressed these holes will continue to multiply and enlarge until the entire brick or masonry falls away from the structure.
You may not be able to completely prevent chimney spalling, but you can minimize its disastrous effects with annual chimney inspections. Your chimney specialist may recommend a masonry sealant to help prevent moisture from penetrating the bricks — a leading cause of chimney spalling.
If you are noticing cracks, holes or missing bricks in the chimney, contact a chimney repair specialist right away. Upon inspection, a chimney repair expert will be able to assess the damage and provide a quote for its immediate repair. Depending on the severity of the spalling, tuck-pointing and brick replacement may be all that is required. In other cases, a portion of the chimney, like the cap for example, may need to be re-built.
Also, it’s not recommended to use the chimney until the full impact of the spalling has been determined. Gaps in the chimney structure that allow water to penetrate could also allow dangerous carbon monoxide fumes to enter the living area of the home during use. Your chimney repair expert will let you know when the chimney is safe for use.