Small cracks in the summer can become surprisingly large cracks by next spring.
Unattended larger cracks in the outer brick will deepen the penetrating effect of rain, snow, and ice.
Chimney fires can ignite instantlythey can sound like an explosion followed by a sound similar to a freight train.
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One of the major causes of chimney fires is damage to the interior clay flue liner and joints.
Creosote builds up in the cracks and eventually will catch fire.
These problems are hard to fix.
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Mostcontractorswill install a metal flue liner to correct the problem.
However, if you are removing and replacing bricks in your chimney, check with your localpermitting office.
In some areas, this kind of work requires a permit and inspection.
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Brick chimney repair is also dependent on seasons and weather.
Do not apply mortar when temperatures are below 40 degrees Fahrenheit.
Instead, wait for favorable temperatures.
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Never work on a damp or wet roof.
Work slowly and carefully when making chimney repairs.
Impatience and hurried work invite accidents.
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Rent fall-arresting harnesses at home improvement centers and tool-rental outlets.
Minor chimney damage may require only cursory work.
But it is a good idea to examine the chimney carefully and complete whatever work is called for.
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Repoint the Chimney Brick Mortar
Mortar holds bricks together.
Typically, gaps form in this area after several seasons.
Water that enters this gap can flow down the sides of the flue.
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Tip
Another source of water damage is the step flashing.
Sometimes the mortar or bricks need to be repaired or replaced around the metal pieces.
Sometimes a good silicone caulking will do the trick.
Even with a recommended 1:4 ratio slope on the crown, moisture will linger in this area.
The solution is a masonry sealer that has a very liquid consistency which can easily penetrate the hairline cracks.
Use the corner of the putty knife to scrape away any loose particles but do not enlarge the crack.
Apply the sealer undiluted with a brush.
One gallon will be adequate for two coats on an average-sized chimney crown.
Replace Cracked Bricks
Severely damaged bricks should be entirelyremoved and replaced.
It is possible to carefullyremove a single brickwithout affecting adjacent bricks.
FAQs.Chimney Safety Institute of America.
