The Most Common Chimney Defects You’ll Ever See

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You might never know from a distance whether a chimney is really safe.

There’s nothing like a cozy fire when the cold winter winds blow. But owning a fireplace is a big responsibility, and one that some homeowners aren’t as familiar with as they should be. That’s why a home inspection covers fireplaces and chimneys so thoroughly. Unlike a defect such as damaged drywall, a bad chimney is a safety hazard.

Here are 5 of the most common defects that you’re likely to find in a home where a wood-burning stove or fireplace is installed:

#1: Heavy Creosote

One of the most dangerous possibilities with any chimney is also one that’s the most likely to happen. Creosote is the natural byproduct of burning a fire. If it’s not cleaned out regularly, it can create one of the most dangerous things to happen in any home, which is a chimney fire.

Creosote is a black substance that’s hard when it’s cold. But when it’s heated up again, it softens, melts and can drip down inside the chimney and into the firebox. Creosote is extremely flammable, which means that a drip can trigger a fire throughout the chimney, which can spread to the whole house. The good news is that when cold, it’s relatively simple to clean creosote out of a chimney using a chimney sweeping brush.

#2: Missing Chimney Cap

A chimney cap is more than just decoration. It protects the chimney from fallen debris and animals nesting inside which block the flue. Homeowners might not even notice if a chimney cap is missing, especially if it blows off during a storm.

Without a cap, the chimney is also susceptible to water damage. Any metal, such as a flue liner, inside the chimney can rust, which makes the fireplace unsafe. Inspectapedia also says that decorative chimney crowns, which resemble a cap but don’t function the same, might not meet local code.

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One fire with a damaged flue is one too many.

#3: Damaged Flue

The flue carries smoke and gases out of the house, but if it’s damaged the homeowner has problems. Mortar can degrade over time, which makes it almost useless. In some very old homes, mortar is in such poor, sandy condition that the bricks can be lifted off effortlessly. That’s how some old, unused chimneys are disassembled.

One of the most common signs of flue damage is visible creosote that has seeped through the bricks. This indicates defective mortar, and it’s a fire hazard. While uncommon in a lined flue, older homes might have a flue with no liner where creosote has built up for years. In many cases, the flue must be rebuilt.

#4: Chimney Cleanout Defects

Many chimneys must have a cleanout. This is a metal door on the flue that’s at least a foot lower than the lowest combustion area. Although a fireplace can also serve as a cleanout in some areas, a wood stove needs a cleanout below the area where the stovepipe enters the flue.

A missing cleanout door where a wood stove is installed is a fire hazard, and it can also allow a buildup of ash that impairs ventilation. If a cleanout is found, a long mirror lets you look up the flue to inspect for damage inside. And if a buildup of debris is found inside the cleanout, that could indicate interior damage such as degrading tile or brick.

#5: Abandoned Chimney

Many older homes once had a fireplace or two that have long since gone out of service. Sometimes homeowners stop using them because the chimneys became unsafe and the cost to repair or rebuild was prohibitive. But an abandoned chimney might spell trouble.

Often, an abandoned chimney is partially removed when a new roof is installed. But partial removal can leave the structure without proper upper support, which can cause it to collapse. The same is true if the chimney is partially removed from a basement. An abandoned chimney needs fun support, or it should be removed from the home.

Fireplace defects are much more than a nuisance that needs repair. Depending on the defects, they can allow gases to back up into the home, impair combustion, cause a chimney fire, or lead to total collapse of the chimney. This is one area where thoroughness in your inspection and the corresponding report could literally save someone’s life.

ICA School believes that a sound, comprehensive education is the best foundation for a qualified home inspector. Through our program, you’ll learn the right way to inspect a chimney, plus every other system in a home. Enroll today, and you can start training tonight for a whole new career that changes your life and and improves the lives of your customers.

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