Water & the Misunderstood Masonry Chimney
What do you think of when you look at your masonry chimney? Maybe you think of the warm fires you enjoy in winter or you wonder how anyone can believe fat Santa could fit in that crowded space. If you look at the chimney and think about the way it’s being bullied by moisture and needs attention, you are a rare and insightful homeowner. It is, unfortunately, normal for people to assume that a chimney is just fine and doing its job well enough while neglecting annual inspections. After all, transferring smoke and combustion gases from the fire to the out-of-doors is pretty much its entire function. How hard could it be? Truth is, chimneys are frequently neglected and misunderstood. The number one enemy of a masonry chimney is moisture, and it can penetrate the structure and cause damage in a lot of different ways. There are costly repairs and various hazards associated with a chimney left unchecked against the frequent onslaught of moisture.
How does water penetrate chimney masonry?
Chimneys are built to keep moisture out. The mortar between the masonry serves to prevent moisture from invading the structure. The chimney crown at the top keeps water from getting between the chimney exterior and the liner or flue. A rain cap is installed at the top so rain doesn’t pour directly into the chimney. Flashing prevents water from entering the home in the connection between the chimney and the rooftop. Even with all of these features in place, moisture can still get in. The following are some of the reasons why and how:
· If the chimney crown develops cracks, moisture can get in. Repair or rebuild is needed.
· Chimney caps have a lifespan of usefulness, and then they need to be repaired or replaced, since they are no longer keeping moisture out.
· Mortar deteriorates much more quickly than masonry does. Eventually, the mortar joints begin to crack and flake off, which allows moisture to penetrate the masonry. A procedure called “tuckpointing” can restore the integrity of the chimney; old mortar is removed and new is added.
· Flashing tends to rust, causing roof leaks. The seal between the chimney and flashing is difficult to achieve properly, and it often fails. When the seal is inadequate, leaks occur and the masonry is more susceptible to moisture.
· A chimney on the low part of a roof can become inundated, if water run-off happens to be directed towards it. A cricket is a water deflector, and one can be built to redirect the rainwater and provide the masonry chimney with a greater level of protection against moisture.
· Masonry materials are usually very porous and able to absorb a lot of water. Common bricks have been compared to absorbent sponges. Waterproofing is a preventative measure that can stop moisture from entering through the porous materials.
What happens when water enters chimney masonry?
Every time there is a freeze and thaw cycle, any moisture in chimney masonry could expand and contract. This process, over time, causes the masonry to crack, and the face of the bricks flake off. Eventually, the chimney structure can become unstable, begin to lean, and ultimately collapse. The following are a few more examples of the types of damage that can occur when moisture enters a chimney system one way or another:
· The protective flue lining can deteriorate and crack, exposing combustible materials to intense temperatures, possibly resulting in a dangerous house fire
· Rusted damper assemblies
· Rusted fireplaces accessories, including glass doors
· A tilting or collapsed chimney structure
· Stained chimney exterior
· Water damaged roof, interior walls, and ceilings
The best protection for a chimney
An annual chimney inspection is recommended for anyone with a fireplace, no matter how infrequently the fireplace may have been used. Professional chimney technicians, such as the trained and certified experts at Chimney Solutions, know how to recognize when moisture damage has occurred. With an annual chimney checkup, you can make sure moisture damage can be stopped before much more expensive damage occurs. Our dedicated chimney sweeps can make all needed chimney repairs and rebuilds. Contact us at Chimney Solutions today at 770-255-1300 so that your chimney isn’t among the neglected ones.