Water = Kryptonite
Brick and Stone structures can last hundreds of years if built properly. Even in Ontario where we experience some of the worlds harshest weather masonry work should stand the test of time. However, even the strongest stone can crack or crumble under certain conditions. Moisture or water is brick and stones kryptonite. Once locked inside water expands and contracts causing cracks, crumbling, and spalling.
Chimneys Prone to Deterioration
Chimneys are especially prone to deterioration for two reasons. One, the by-products of combustion include water vapor. If the flu gasses get cool enough condensation can form inside the chimney before escaping into the air. Two, water from snow and / or rain can enter the chimney cap if not sealed properly. Either can compromise the whole structure of the chimney. These are two good reasons to hire a qualified (red seal) mason to build your chimney. Chances are that issues caused by a poorly constructed chimney will take years to see. That “weekend warrior” mason will be long gone by that time.
A Qualified mason with experience building chimneys will take care to align and seal your clay flues not leaving areas for flu gasses to escape, cool, and condense inside. They also will take extra care to use superior materials to cap the chimney and prevent moisture from entering from above.
Weepers
The first three rows of brick or stone is also an area of concern because of water. Masons use “weeping holes” to allow water to escape from behind the wall. Good masons take care not to let anything including excessive mortar block the weeping holes. When water can’t escape from behind the wall, lower bricks become saturated and quickly loose their strength and integrity. Again, the whole structure can be compromised or undermined by water.
High-rise buildings commonly have issues with blocked weepers above four stories. In high brick buildings weepers are required every story. Once masons begin building exterior walls from the inside, sometimes not as much attention is given to the all-important weeper hole. That is why you often see aluminum siding going up, covering higher spalling bricks (usually starting at the fifth floor) on older high-rise buildings.
Prevention
Stopping water, the underlying cause of cracking and spalling, is a mason’s chief concern. Inspect your chimney annually and make sure water hasn’t found a way in. You can also protect your home including your chimney with waterproofing agents or sealers. Some bricks are coated with an exterior sealant during their manufacturing process. That is why sandblasting brick walls to clean them isn’t always a good idea. It can make your wall vulnerable to water. A good mason knows their material and the best ways to use them.
We Can Help
Whether you want us to inspect your chimney or need a cracking or spalling problem fixed, Call Masonry Nation! We are Ottawa area’s chimney and fireplace specialists. Visit masonrynation.com.