Do Chimney Cleaning Logs Really Work?

Regular chimney cleaning is one of those chores that comes with ensuring the safe and efficient operation of wood-burning fireplaces and heating stoves. Chimney cleaning logs have been growing in popularity. While many homeowners use them, some mistakenly believe it is a substitute for manual chimney cleaning. Chimney cleaning logs, also known as creosote sweeping logs (CSL), are advertised as a quick and easy way to clean the chimney. But do they really work?

 Creosote cleaning logs?

Creosote cleaning logs are a specially formulated compound that contains chemicals and other additives to help reduce creosote build-up in the chimney.They are manufactured specifically for use in wood-burning fireplaces and wood stoves.

How do they work?

After burning one or two wood logs, a CSL is placed directly on the hot embers after the flames are completely out. When you light the CSL with a match, the combustion begins to break down the compounds in the log, releasing the cleaning chemicals into the flue. The substances adhere to the creosote turning it into powdery ash. The chimney sweep can easily remove the ash powder inside the chimney and fireplace.

Are creosote sweeping logs toxic

Yes, CSLs contain toxic chemicals. It’s essential to follow the manufacturer’s directions. Due to their toxicity, your damper will need to remain open until the fumes have been expelled. CSLs cannot be used if there are any obstructions like pests, nests, and other debris blocking the flue. You should have a qualified chimney professional inspect your chimney before using CSLs. Also, fireplace doors and screens should remain closed when burning CSLs. The chemicals in the cleaning log are flammable, and there is also a danger of a hot ember or downdraft, causing a fire. They should be used with caution. It is recommended that you avoid using fans or other heating equipment while using cleaning logs to avoid circulating fumes throughout your home.

The problem with creosote

Creosote is a naturally produced by-product of the chemical reaction during combustion. It adheres to the walls inside the flue and other components as contaminants are expelled through the chimney. It continues to accumulate with every burning log and becomes a thick, tarry, highly flammable substance in excessive quantities. Excessive creosote in the chimney is the leading cause of house fires.

Why you still need a professional chimney sweep

While chimney cleaning logs can reduce creosote accumulation, it doesn’t entirely remove it or prevent it. The Chimney Safety Institute of America (CSIA) and CSL manufacturers will tell you that chimney cleaning logs are no substitute for a professional chimney cleaning and inspection.

CSLs can help minimize creosote between cleanings, but you will still need a qualified chimney sweep to clean the ash and any chemical residue remaining from the cleaning logs.  Annual chimney inspections are also necessary to inspect for blockages and other damages that may need repair.