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5 Common Safety Issues For Chimneys In Older Homes

5 Common Safety Issues For Chimneys In Older Homes


Fireplaces are a common feature in most older homes. Patio fireplaces, wood-burning fireplaces, and masonry chimneys are all popular features that pose safety hazards for homeowners. Aging mortar and brickwork can cause these structures to become more susceptible to overheating, carbon monoxide leaks, and the lack of updated codes. You must know these dangers exist when looking at a potential home purchase or remodeling project. Some of the most common safety issues for chimneys in older homes are the following.

Chimney Obstruction

Chimney obstruction is a problem that may not have immediate effects, but it can lead to severe consequences over time. An obstruction in the chimney causes a reduction in airflow. This restriction can cause a dangerous buildup of carbon monoxide as gases and fumes cannot exit the chimney. A gradual buildup of creosote-like residue on heated surfaces can also lead to a fire hazard. Over time, this buildup will cause flammable vapors to accumulate and ignite upon exposure to open flames.

Inadequate Venting

Inadequate ventilation in a fireplace is the most common cause of chimney fires. Exhaust vents near the top of the fireplace or the flue area must be on a safe, direct trajectory to avoid obstructions. If they back up and or reverse their direction, they can cause the failure of the chimney liner's structural supports and may cause severe damage to your home's indoor air quality. The Chimney Safety Institute of America recommends changing vents as often as every five years.


Creosote is a dark, waxy residue that forms on creosote-treated wood near fireplaces and masonry chimneys. Creosote can cause fires in the chimney, providing an ignition source for other combustibles inside the home. Creosote buildup also causes toxic fumes to accumulate in your home. Harmful carbon monoxide fumes pass into your home if creosote buildup causes your chimney to become blocked or fails.

Masonry Chimney

Masonry chimneys often become damaged during construction over the years. Damaged chimneys can be unsightly and may also cause structural damage to your home during a fire. Excessive damage can also lead to cracks and failures that may lead to structural failures of the masonry walls and foundation.

Cracks in the Flue

Cracks in the chimney flue are expected during construction, but they can be dangerous if they lead to a complete failure. Many chimney failures occur due to broken lath or inadequate masonry reinforcements inside the chimney. Cracks can also develop from other routine wear and tear on the structure from weathering and neglect. Cracks that form in masonry walls and liners may cause dangerous liquefaction of materials debris falling into your home.


Chimney safety during construction and remodeling is an important consideration. As old homes are renovated, it is essential to take safety precautions, including checking the chimney for obstruction, flue failure, and maintenance of the chimney structure. Contact us for a chimney sweep in Ambler, PA.

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