The most frequent reason why fires occur in chimneys, is the lack of cleanliness of the duct through which the smoke and other waste produced in the combustion rise, these create a sticky and odorous layer on the walls of the ducts. , which is also highly flammable.
If the hygiene of our chimney is not good enough, the circumstance that favors the start of a fire may occur.
Start and development of a chimney fire
No chimney fire originates and develops in the same place and way, because it influences aspects such as construction, length, travel, joints, obstructions, or type of creosote of the chimney.
In any case, the fire is usually initiated by a violent initial deflagration, accompanied by a characteristic sound and pressure waves, which can lead to deterioration of the flue pipe.
Subsequently, the fire will move along the entire conduit, burning the deposited creosote, generating a great pressure inside and a blowtorch effect at its exit with characteristic sound – roar
Defects caused by fire and pressure waves can be considerable. However, there are cases in which the fire occurs in a slow manner and with hardly any signs that indicate that a fire is occurring inside the chimney.
How to prevent Chimney Fire
Chimneys that are lit regularly must be conditioned and cleaned thoroughly, fundamentally, the chimney draft. It is important to remove the creosote (resin) adhered to the walls of the duct, since this is what ignites and causes the flames inside the duct.
Start the fire
The use of dry wood is recommended. Dry wood burning produces less creosote than wet wood. Likewise, woods of species such as oak or holm oak are preferable, which are harder and have a higher calorific value because they produce less creosote than softwoods such as poplar or fir. On the other hand, the use of high combustion products is discouraged until it is in perfect condition, and do not use gasoline or products that accelerate combustion to ignite the fire.
They also offer a good measure of prevention, ventilation in the rooms where the fireplace is located, since the fire consumes oxygen and generates carbon monoxide. Good ventilation improves the draft or natural movement of smoke inside the duct and facilitates the removal of carbon monoxide.
It is advisable not to place carpets, furniture or clothes in front of the fireplace, because they can burn due to the heat received by radiation. All combustible materials must be kept more than one meter away from the home.
It is discouraged to leave the fireplace lit when we go to sleep because it is dangerous in the event of a possible outbreak of fire. It must be turned off when the house is empty.
An excellent preventive measure in those houses that have a chimney, is the installation of a fire detector.