Chimneys can be the most dangerous thing in your house. That’s because so few people make sure they are ever cleaned.
Creosote will ignite at 451 degrees, about the same ignition rates as ordinary paper. It can turn anybody’s chimney into an inferno of 2100 degrees within seconds. A chimney fire in an older house can transfer to the wood structure and result in a disaster. Home flues equipped with wood burning stoves especially should be inspected once a year.
Not only wood burning chimneys are risky. Dangerous deposits can build up in any flue, even those with venting coal, oil or gas furnaces. It helps to install a metal flue liner, aluminum for natural gas furnaces and still for hotter, oil burning furnaces. Installation of a liner usually costs 500-700 for aluminum and 700 – 900 for steel. In place, the metal will greatly outlast file brick or ceramic tile. The round metal liners are said to draw more rapidly and eliminate poisonous vapors more efficiently than traditional masonry work. To prevent the spread of heat into home timbers or walls, areas between the liners and chimneys inner walls are insulated to the control of the heat of the metal.
In older neighborhoods where oil heat fumes were vented, heavy sulphur deposits result. If, at some later time, a homeowner converts his chimney to a high efficiency gas furnace, the heavy moisture will form sulphuric acid. Clay chimney linings disintegrate under the assault of the acid and collapse on themselves. This could further block a flue and force deadly carbon monoxide into the home through cracks or out a fireplace or firebox.
Local governments have often been forced to start mass inspections of flues to control such a carbon monoxide and sulphur problem. It’s an indication that chimney sweeps do not just serve the wood burning customer.
Other heat sources can be dangerous if not professionally watched. Chimney conditions are often overlooked in otherwise complex realty contracts and sometimes skipped over by professional engineering inspections. The building code bans the blending of home furnace gases and fireplace combustion in one flue. An inspection should also determine the condition of the middle wall between separate flues in a masonry chimney. Ideally, a sweep cleans the system from the top down using a stiff brush to scrape down the side of a flue. The sweep also scrapes out deposits in the smoke chamber and firebox, inspects for holes or loose masonry and vacuums out loose debris. Some chimneys don’t need to be cleaned every year at least not to remove creosote accumulation. But even id no fires have been lit, open chimneys can be clogged by bird and squirrel nests and leaves. An annual inspection will eliminate those problems, which can also be prevented by a chimney cap or screen.
Coals can stay hot for a long time. Put them in a metal container and let them cool outdoors. Never leave a roaring fire unattended. Have a fire extinguisher and the working number of smoke detectors in the home. Test the smoke detector batteries regularly and replace when needed. Schedule chimney and flue inspections on a yearly basis. Don’t burn holiday wrappings and colorful papers like the comics in a fireplace. They emit toxins. Also avoid treated wood and plywood because of toxic chemicals.
Chimneys needs to be cleaned regularly, depending on how much you use it. As you can see this one is very dirty and could cause a chimney fire at any time. We got there in time to clean the chimney.