A chimney is often one of the most overlooked structures on a home. That’s because most people think since it’s built of brick or stone, it must be more durable than the rest of their home. While it’s certainly true a well-built chimney can outlast the rest of your home, just like everything else, chimneys need to be maintained.
Deteriorated/powdery mortar or loose brick, falling pieces of brick & mortar, water damage inside, smoke migration into living spaces – these are all signs that a chimney needs attention. Chimney damage and erosion is entirely preventable with regular inspections and maintenance. If you haven’t had a close look at your chimney for a long while, or if you have an uncomfortable feeling your chimney is not in good shape, we can help.
One of the biggest challenges for a brick and mortar chimney is the “freeze -thaw” cycle. Water seeps into cracks and holes within your bricks and joints and freezes. The expanding ice will push apart bricks and damage mortar joints. Cracks get bigger and the damage accelerates.
Once mortar starts deteriorating from exposure to weather, it becomes much more absorbent. A common repair for deteriorated mortar joints is called repointing. We cut the mortar joint to appropriate depth, then repack the joint with new mortar. A good repointing job, using proper materials, will give the chimney a much longer life span and enhance the chimney's appearance.
As fires burn, they generate smoke. As the smoke rises, it comes into contact with the cooler interior of the chimney (the flue), where some of the smoke condenses into creosote. Creosote is a black or brown gummy substance that builds up on the flue walls.
Once enough creosote builds up, it can close off the opening preventing a proper draught, and in a worst-case scenario, can start a chimney fire. A chimney fire can cause the overheated bricks and mortar to crack and crumble providing an avenue for carbon monoxide to enter your home.
The chimney crown covers and seals the top of the chimney from the flue liner to the chimney edge. The crown should provide a downward slope that will direct the water away from the flue to the edge of the crown. The overhanging drip edge allows the water run-off from the crown away from the chimney and helps prevent erosion of the brick and mortar on the chimney’s vertical surfaces.
Flashing is the seal between the roofing material and the chimney. Flashing prevents rainwater or snow melt from running down the chimney into living spaces where it can damage ceilings and walls and cause rot in rafters. It is designed to allow both the roof and the chimney to expand and contract at their own rates without breaking the waterproof seal. If the seal does break, erosion damage occurs quickly in Victoria’s rainy winters.
Chimney caps, also called rain covers, are the best and most inexpensive investment for long-term protection because of its ability to protect the entire chimney crown. It will prevent birds and animals from entering and nesting in the chimney and help prevent sparks from landing on the roof or other nearby combustible material.
Creosote in a Brick Chimney