Cracked Chimney Flue Tiles: What You Need to Know
If your chimney uses a clay tile liner, it will likely develop some cracks over time. A compromised chimney liner can lead to all sorts of problems, the worst of which is a house fire.
Chimney Specialists of Highland, WI, would like to share some helpful information about cracked flue tiles and how to resolve this problem.
Chimney liners 101
It’s a legal requirement today that all chimneys have a proper chimney liner. The most common styles of liners are:
- Clay tile
- Poured-in-place compounds
- Stainless-steel liners
For many years, clay tile liners were in fashion because they’re less expensive to install than the other two types. But they’re not as durable.
What makes clay tile liners crack?
Uneven heat distribution in the flue during a fireplace fire is probably the most common cause of cracked flue tiles. Clay doesn’t absorb heat as efficiently as other liner materials, and the uneven absorption leads to buckling and cracking in select tiles.
Less common causes of cracking include major structural damage to the chimney, such as with a lightning strike, and combustion gases and creosote acids, which can gradually eat away at a liner’s surfaces.
Worst-case scenarios with a damaged clay chimney liner
As noted, a house fire is the most serious concern when flue tiles begin to crack and fall away. Any breach in the liner surface will allow intense heat and flames to escape and possibly come into contact with home building materials, depending on where the breach is.
Studies have shown that nearby woodwork in a home can catch fire in as little as three and a half hours when a clay tile chimney liner is damaged and contains open spaces.
Other problems that can be caused by damaged liners
Escape of carbon monoxide
Carbon monoxide is a dangerous and potentially fatal gas produced in varying amounts during fireplace use. One of the functions of a chimney liner is to contain this and other combustion gases and channel them up and out of the chimney.
You can’t smell or see carbon monoxide, but it’s highly poisonous when inhaled by people and animals. Along with keeping your chimney liner in good repair, you should have working CO monitors near the fireplace.
Reduced efficiency
A liner with breaks in it won’t provide an efficient draft. This can cause fires to burn incompletely and produce much more smoke. It can also result in smoke and gases backing up through the fireplace into the room.
Structural damage
When smoke, acids and combustion gases escape from the flue, they can damage the interior masonry of the chimney. This is a particular problem because the gradual and ongoing damage happens in an area you can’t see.
Chimney liner repair and replacement
Chimney companies have the tools and experience to repair minor clay tile liner issues. If damage is significant, your technician likely will recommend installing a new liner made from more durable stainless steel or a poured-in-place compound.
Have your flue inspected
A proper chimney inspection will quickly alert you to problems happening with your chimney liner. This is the first step to addressing cracked tiles and other damage inside the flue.
Chimney Specialists is here to help with all your chimney liner needs. We provide repair, inspection and liner-replacement services. We work throughout the Highland, WI, and Dubuque, IA, areas.
Chimney Specialists Inc. (608) 929-4887
869 Main Street, Highland, WI
