Unlined Chimneys: A Problem Found in Many Older Homes
The streets of the United States are lined with millions of charming older and historic homes like stately Victorian mansions, colonial homes and other architecture styles that were built during the housing boom in the late 19th century through the early 20th century.
This was a period of time when fireplaces and wood stoves were the traditional source of heat and it is common to find one or the other in just about every room in the home. But as impressive as many of these older homes are, they share one common and potentially dangerous trait – they were often built with an unlined chimney.
In fact, unlined chimneys are a problem found in many older homes built before modern building codes began requiring them in the 1950s and 60s. And with temperatures of wood burning fireplaces, wood stoves and other fossil fuel appliances reaching up to 1500 degrees, an unlined chimney can cause a number of problems.
Homes with an unlined chimney are at a greater risk of chimney fires. With temperatures that can soar to well over 1,200°F, the sizzling heat and intense fumes along with burning embers can be a recipe for igniting a roof fire. Once ablaze the fire can quickly spread to other combustible materials quickly engulfing an entire home in a matter of minutes. A chimney liner insulates the chimney from the high heat and helps control burning embers allowing the chimney to work more efficiently.
More costly to clean and maintain
Without a liner, it will be more costly to clean and maintain the chimney. Creosote is a natural by-product of the combustion process and this slick substance sticks to the masonry walls inside the chimney and continues to accumulate each time the fireplace is used. Since it’s also a highly combustible material more frequent and intensive chimney sweeps are needed. The chimney sweep may also need to spend more time scrubbing away the creosote. Installing a UL-listed chimney liner will reduce the amount of creosote residue in the chimney making it easier to clean and maintain.
Increased risk of carbon monoxide exposure
Without a chimney liner to insulate the chimney, occupants are at an increased risk of exposure to carbon monoxide poisoning. The intense heat inside the chimney can cause small cracks and crevices in the masonry. While most of the smoke and fumes are expelled through the chimney, some smoke and dangerous gases can travel to other rooms in the home through these tiny holes. The risk is even greater when a burst of wind causes a sudden down-draft. Because it is an odorless and colorless gas, carbon monoxide is often called the invisible killer. It is recommended homeowners install a chimney liner to reduce the risk of exposure to dangerous fumes.
More expensive chimney repairs
During a chimney inspection, chimney sweeps are likely to encounter more repair work in an unlined chimney. Without a chimney liner for protection from the elements, the exposed brick and mortar will deteriorate at an accelerated pace as condensation develops inside the chimney walls. This can result in a large number of damaged, missing and spalling bricks that will need to be repaired or replaced increasing the cost of chimney repairs.
Consult with one of our CSIA-certified chimney sweeps about installing a chimney liner in your home today.