Creosote Removal

A major contributory factor in chimney fires is the build up of creosote in the chimney and flue liners. It's an inescapable fact that dirty chimneys can cause chimney fires and creosote is a major player here.  We can inspect and remove.

Chimney fire temperatures can reach 2000 degrees which is more than enough to damage the chimney and in the worst-case scenarios destroy homes, even lives. Often the chimney fire is not dramatic enough to be noticed yet the damage can be severe even allowing fumes to penetrate the building through compromised structures. Chimney fires are entirely preventable when you know why they occur. 

Creosote: What is It?

Creosote is a flammable and corrosive substance which builds up on the walls of your fireplace and chimney flue.

It is formed when unburned wood particles, loose ash and other gasses from the burning process combine as they traverse the chimney. Unburned particles and gasses condense and build up on the inner surfaces of your flue and chimney. Given time this tar like coating can become a danger, it is flammable and can easily be ignited by the fire below.

Excessive deposits will restrict the flue which will reduce air draft accelerating the condition. In extreme cases it can block the chimney entirely, clearly a danger to the wellbeing of occupants.

Creosote: How to prevent it?

If you have creosote build-up in your chimney then look at how and what you burn in your stove or fireplace as that may provide the key.

Kiln dried wood having less than 20% water content is by far the best you can burn. High moisture content in wood will burn less efficiently, the fire will create steam which reduces the temperature that the fire burns at giving ideal conditions for creosote deposits. Even if the wood feels dry on the outside water can make up 50% of the weight and will take years to dry naturally. A stove or fireplace that is not working efficiently may also burn at too low a temperature again causing ideal conditions for creosote build-up. It's not a good idea to burn smokeless fuels and wood at the same time either, both need to burn at different temperatures and the mixture of deposits is acidic and can cause corrosion in a chimney liner. Burn one fuel, HOT!

WOOD as a Fuel - DO'S and DON'TS

When firewood burns, it breaks down to its components. Its moisture content evaporates.

The oils in the wood vaporize and become volatile gases.

Black carbon and other particles mix with the gases in smoke. The logs become a glowing mass of charcoal. Finally there remains ash, a mix of fire-resistant, mineral-rich dust. When wood burns slowly, at a low temperature, incomplete combustion results. The oils in the wood vaporize but the resulting carbon-rich gases fail to burn. Instead they rise up the chimney as smoke. 

wood burning hot to prevent creosote build up

Consequently:

• Much of the firewood's heat is wasted.

• The smoke pollutes the neighbourhood and the environment, causing health problems.

• If the chimney cools to below 250°F the gases in the smoke condense into a liquid, combine with water and black carbon, and form creosote.

Creosote is smelly, black, corrosive and flammable. It may run down inside chimneys and stovepipes as a dark goo that oozes out of cracks and joints. As a solid, creosote forms a hard, glass-like, difficult-to-remove coating on the inner surface of the chimney.

Or it can form soot, a fluffy mess that plugs stovepipe and chimney. Over a heating season creosote can build up to a layer several inches thick. The problem feeds on itself. The fire in the stove is deprived of draught, so the burn slows further, creating more creosote. To prevent creosote from forming, we must either keep the chimney above 250°F all the way to the top, or burn up the gases liberated from the burning wood before they can reach the chimney. Keeping a whole chimney hot would, of course, waste huge amounts of energy. Modern stoves recirculate the gases or use catalytic converters. Either way they burn up the smoke within the stove and capture the heat produced. You can achieve the same result regardless of the type of stove you have: The key is to burn hot fires, do so with care.

Paradoxically, to avoid creosote formation we must burn our wood fires hot. On the other hand, a hot fire in the stove with the air control wide open may allow hot oxygen into the chimney, where it can ignite the creosote, causing a chimney fire. The whole building may catch on fire if the hot chimney ignites combustible materials sparks land on a combustible roof.
Since creosote build-up restricts flow, which slows the smoke on its way out, allowing more time for it to cool and more creosote to condense, restricting the flow further.

A CLEAN PROPERLY MAINTAINED CHIMNEY WITH A GOOD DRAUGHT IS A PREREQUISITE OF SAFE WOOD BURNING

The document below is a more detailed, printable PDF file, 
we encourage you to download it, read it and put what you learn into practice.
It may save you more than just money!
Click on the image to download.