Chimney Cleaning

During the winter months, fire departments all over the country frequently respond to chimney fires. Homeowners should be extra cautious when it comes to the care and maintenance of their chimneys.

What are Chimney Cleaning Logs?

When wood or coal burns, a byproduct of tar, ash and carbon residue sticks to the inside of the chimney. That byproduct is called creosote, which is highly flammable. If it is not cleaned out, it can create a serious fire hazard. Also know as "creosote destruction logs," chimney cleaning logs work on the principle of chemical destruction of creosote and soot.

They are a "do-it-yourself" way to clean the chimney - convenient and inexpensive compared to traditional chimney cleaning methods.

How do Chimney Cleaning Logs Work?

The logs are charged with chemicals that are released as the log burns in the fireplace, usually for up to about two hours. The smoke from the log, filled with those minerals, floats up the chimney, and seeps into the creosote. After about 10-to-15 days, the chemicals in the smoke cause the creosote to eventually dry-out and flake-off. The process is called a catalytic treatment.

How Effective are Chimney Cleaning Logs?

It depends. Unfortunately, many variables (such as the type of fuel burned, the rate of burning, and the heat intensity that generated the creosote), combine to determine how effective the cleaning logs will be.

Given the right conditions, however, the chemicals can destroy and remove all of the built-up creosote and keep the chimney creosote-free.

Are the Logs Effective in all Fireplace Types?

No. The logs are primarily effective in sealed, controlled, combustion-type stoves and inserts - they do not work in open-flame fireplaces (the common, open-hearth fireplace). The problem with open-flame fireplaces is that the "reactive gas" (see below) necessary to clean the creosote will be too diluted to be effective. Or in other words, the reactive gas is carried out the top of the chimney before it can condense and attack built-up creosote.

What Chemicals are Used in the Chimney Cleaning Logs?

Inorganic salts, such as a mixture of potassium nitrate and ammonium sulfate, break down under heat to form a reactive gas that condenses on the inside of the chimney flue. The reactive gases fall into one or more of the following categories: acidic gas, alkaline metals, transition metals (copper, zinc, etc.), or surfactants, either singly or in combinations. These condensed reactive gases react with the creosote to remove it.

Are There Differences Between Chimney Cleaning Logs?

Yes. The basic difference is the composition and concentration of the chemicals. Only one log product is patented, UL-certified, and independent lab tested (OMNI-Test 503 643 3788) to clean creosote. It is a product manufactured in Holland and distributed in the USA by Joseph Enterprises at under the label of CSL logs.

What are Other Chimney-Cleaning Options?

  • Chemical chimney-cleaning products are available in bulk from fireplace stores or on the web.
  • A professional chimney sweep should be hired about once a year to perform a thorough cleaning and maintenance check.