Problems with Chimneys in Old Houses


Traditional masonry chimneys were one of the original styles of chimney construction, and this construction is still commonly used today. They are so popular because of their aesthetic appeal and their robustness, often holding up for many decades or even centuries. Because of their longevity, many masonry chimneys still stand today but often suffer from issues related to age.

Older Home with Chimney - Aurora IL

The one weakness of a masonry chimney actually lies in its potential for water damage. Masonry materials like brick, mortar, and concrete have a very porous makeup, so they readily absorb water. For older chimneys that have been around for many years, they have likely absorbed a lot of water. During winter months when temperatures fall below freezing, the water undergoes a freeze and thaw cycle in which it continuously expands and contracts. The masonry that has absorbed water also experiences this swelling and shrinking. After many winters of this, the materials start to degrade. This is evident by the presence of cracked mortar, missing bricks, and even collapse. When a chimney in this state is used, the smoke and other toxic fumes can seep through the holes and crack into the living space. Repair options include tuckpointing for minor mortar damage and a complete rebuild, depending on the extent of the damage.

Another common issue with older chimneys is their size. The logic behind building chimneys used to be the bigger the better, but studies have proven that an ideal size chimney exists for every size of fireplace. The chimney functions by way of draft, or air flow. Hot air from the fire rises through the chimney, drawing air from inside the house and through the fire. This directional air flow is vital for sustaining a good fire. When the chimney is too wide, the hot air has more space to spread out, and thus, it cools faster. This slows the rise of air, sometimes to the point of reversing it, which results in smoke backing up into the house. A chimney and fireplace specialist can address this issue by adding a properly sized chimney liner.

Speaking of chimney liners, older chimneys often do not have them. The creosote and soot created by the fires over many years has built up directly on the masonry. When combined with water vapor, the soot can become acidic and eat away at the brick and mortar. Again, this issue can be fixed by installing a chimney liner, made of heat and acid resistant stainless steel or ceramic.

An older home offers plenty of charm and character, but the aged chimney that came with it may need some special attention to function safely. A chimney inspection, which should be done annually, anyway, can determine what your chimney needs. If you live in the Aurora, Illinois area, contact the chimney experts at Pozzi Chimney Sweep to schedule an inspection.