Don’t Ignore This Summer Chimney Warning: The Surprising Cause of Creosote Buildup
Here we are again, on the cusp of Pumpkin Spice season with cooler mornings leading to warm afternoons. As we move through this summer season, we’ve noticed a recurring trend of advanced chemical cleanings needed more frequently rather than your standard sweepings.
Many of our customers, even those who have kept up with their annual chimney sweepings, are experiencing unprecedented creosote buildup.
This alarming trend highlights the need for greater awareness of how creosote forms and why regular chimney maintenance is essential—even if you’re not a heavy fireplace user.
How Creosote is Formed
Creosote accumulates in your chimney due to a combination of three key factors: time, temperature, and turbulence (the Three Ts).
Time
This year, the warmer winter has played a significant role in how creosote is formed. An updraft is created by the temperature differential between cold outside air and warm flue temperature. When the temperature difference is marginal, the draft is negatively affected. The slow draw increases the residence time of the smoke, leading to more creosote deposits forming on the internal flue walls.
Temperature
Long burn smoldering fires produce a lot of creosote, while small hot fires result in the most efficient burn. In the past, slow burn fires were common with the method referred to “dampering down”. This has since been refuted and is no longer viewed as an acceptable practice due to the increased risk in chimney fires.
Turbulence
The more offsets or bends a venting system has, the more resistance to flow there is. Friction will always exist between moving flue gases and the passageway, but the more obstacles there are to maneuver, the longer the residence time.
Why Sweepings Are Crucial
Because there are so many factors that contribute to creosote buildup, even if you don’t use your fireplace frequently, you can still develop enough creosote to pose a serious fire hazard. Regular inspections and sweepings help mitigate the risk and ensures your chimney operates safely and efficiently.
Addressing Moisture Concerns in Firewood
When we find excessive creosote, one of the first concerns we address with homeowners is the moisture content of their firewood. Ideally, firewood should have a moisture reading of 15% or lower. However, many people are unaware that moisture readings taken from the surface of the wood can be misleading. It’s crucial to split the wood and measure the internal moisture, as we’ve found that even firewood advertised as “low moisture” can have internal readings of 25% or more.
By staying informed and proactive, you can keep your chimney safe and your home warm and cozy throughout the year. If you haven’t scheduled your annual sweeping or are concerned about creosote buildup, now is the time to act.
The post Don’t Ignore This Summer Chimney Warning: The Surprising Cause of Creosote Buildup appeared first on Boston's Best Chimney.
