Burn only dry and clean wood

The cold season tempts you to light a fire in the hearth and enjoy the pleasant atmosphere created by the warmth of the wood stove. The downside of burning wood is the hydrocarbons and small particles produced by burning, which enter the respiratory tract and pollute the air. Especially in windless weather and during periods of low pressure, smoke stays close to the surface of the Earth and can be a locally significant factor affecting air quality.

When wood is burnt correctly, it is possible to minimise the detriment caused by combustion and maximise the thermal energy produced by the wood.

−The most important thing is to always burn wood that’s dry and clean enough, Jyväskylä’s Director of Environmental Protection, Petteri Ahonen, points out.

−Painted, varnished or otherwise processed wood, plywood or chipboard are also unsuitable for a fireplace or sauna firebox, as harmful compounds are generated by burning them.

Small amounts of cardboard can be used in ignition, but cardboard and paperboard should otherwise not be used.

−The Waste Act stipulates that paperboard must primarily be recycled.  Secondly, cardboard burns quickly, and results in a lot of ashes and soot. Burning rubbish can also damage the fireplace.

Smoke colour says a lot

The wood burns more efficiently when placed horizontally. Petteri Ahonen advises that a sauna firebox or wood-burning oven, for instance, should be filled relatively loosely to allow air to circulate the chamber.

−Wood shouldn’t be added during full fire but only after the load of wood has nearly burnt to the end. 

During wood-burning, it is a good idea to observe the colour and amount of smoke. 

−During the first few minutes of heating, the pale-coloured smoke rising from the chimney is part of the process, but if dark smoke rises from the chimney for a long time, the wood isn’t dry enough or wood that isn’t clean was selected for burning.

According to Mr Ahonen, contact is made to some extent with Environmental Protection that is connected with smoke detriment in residential areas. 

−In these cases, we check to see if it’s a question of burning waste wood, paperboard or rubbish, and we provide guidelines for recycling wastes. 

−Sometimes people are disturbed by smoke in their yards. The solution may be the installation of a longer chimney or placing the pile in a different part of the property.

Firewood must not be stacked on the terrace

The terrace or the wall of the house is not the right place to store firewood: rather, firewood must always be stored far enough away from buildings. A basic principle to observe can be the eight metres of distance derived from the building codes. 

According to Henna Kettunen, leading fire inspector of the Central Finland Rescue Service, wood stacked near the building pose a significant risk, because when a fire starts, it quickly spreads from the terrace to the inside of the building or moves from the wall of the building along the wall and structures towards the eaves of the roof, from where the fire quickly spreads to the upper floor and roof structures.

−If, due to the small size of the property, a distance of eight metres isn’t possible, the building construction supervision authorities must ascertain the requirements to build a separate lockable woodshed.

A garage is also not suitable for storing wood, but if there is a separate closed storage facility indicated in the building permit in connection with the garage building, you can store firewood in the facility.

−The storage of firewood indoors must not endanger the fire safety of the building. Small amounts of wood can be stored indoors on a temporary basis, but wood should not be directly positioned close to a fireplace door, Ms Kettunen emphasises.  

In permanent housing, a chimneysweep should sweep hearths and flues each year, and every three years in the case of leisure housing. 

−An unused fireplace or flue does not need to be swept, but a fireplace and chimney that have not been used for three years should be swept before putting them to use.

Check the building codes

Building a new hearth or wood stove in a detached house is subject to licence. Mikko Holmberg, leading building inspector for the City of Jyväskylä, notes that the floor plan attached to the building permit application must show where the fireplace and a possible new flue will be placed, as well as what kind of flue it is in connection with the information on the protective distance.

−The technical specifications of the fireplace should also be included with the application. These are generally found from the hearth suppliers’ brochures, which can be attached to the application.

During the construction phase, it is the foreman’s responsibility to ensure that the protective distances are fulfilled and that the firewall is properly protected against fire. 

−If, on the other hand, a new hearth is going to be built to replace one being removed, no building permit is customarily required under these circumstances, Mr Holmberg states.

Text: Pia Tervoja
Image: Timo Sillanpää