The story on soot

How well are you utilizing your wood burning system? Sure, you can walk outside and look at the flue when you’re burning to see whether you have dark heavy soot smoke, grey smoke or mostly steam. Of course, the dark heavy soot is laden with flammable particles and means you aren’t burning hot enough or that you’ve just started your fire. The grey smoke may also appear upon start-up or can depend on the type of wood you are burning. The grey steam that dissipates into the air is the best indication of a clean burn. But wait, isn’t there an easier way to tell how you are doing?

When it comes to wood stoves, the best measurement tool is a stove thermometer. Burning a stove without a good thermometer is like trying to drive your car without a speedometer. Stove thermometers tell you when the fire is too cool, hot enough or too hot. It’s also fun to watch it respond to the changes you make when burning wood. If you don’t’ have a thermometer –get one today!

If you notice a metallic smell and your stove or stovepipe starts to take on a whitish or reddish glow, it’s too hot. If your stovepipe turns a whitish or grey color even when it is cool, that means you are burning way too hot! Again, get a thermometer.

Another important measurement tool is actually the residue left from burning. This applies not only to a woodstove, but also to a fireplace. The morning after a fire, you want to find ashes that are black, grayish black or grey. What you don’t want to find are unconsumed pieces of wood. This means the wood smoldered for hours. Just as bad is shiny black coals. You probably have quite a build-up of creosote in the flue. This creosote will most likely lead to a chimney fire if it’s not cleaned up.

This residue in the flue can take on different forms. If you notice a tar seeping through the mortar joints and brick, this means you have a nasty creosote problem. Our Certified Chimney Sweeps at Lindemann can take care of this problem. If you look up the flue with a flashlight and see a shiny black creosote, this means that nasty tar has been baked onto the inside of the flue. It is now as hard as enamel and impossible to get off without special treatment and tools. Again, we can fix you up. If you notice a residue like expanded foam, this means that that tar that baked on ignited and there has been a chimney fire. The chimney immediately needs inspected for worthiness and we will use an internal video inspection camera. Chimney fires can damage a chimney making it dangerous to burn if it goes untreated. The best result is a few cups of soot resembling coffee grounds when the flue is brushed.

If you have a masonry chimney and find chunks of mortar or bits of orange clay flue tile in your soot residue, immediately call us at 847-739-4199. Mortar that holds the brick and flue tile liners is likely falling out and you need to have this repaired or the flue relined before continuing to use it. If it’s the orange clay tile, you could be having a deterioration problem or there could be damaged. Flue tiles are your first line of defense that keeps the products of combustion contained within the flue so it doesn’t migrate into your home.