Wood has been used as a building material since people have had a roof over their heads. As long as the building exists, the built-up wood is removed from the natural cycle of nature and must be protected from organisms for which wood is the staple food. If timber structures become infested with insects or dry rot, the thermal preservation of wood provides effective ways to curb the destroyers. In this way, the protein compounds of the organisms are destroyed by heat, so they die. These alternative wood preservation methods are reliable and effective, so that from today’s perspective, there is no reason not to thermally treat static wood that is worth preserving. However, thermal wood preservation methods are only suitable for killing existing pests effectively in order to preserve the wooden components from further damage. They are not a preventative measure to protect healthy wood from attack.
What wood thermal preservation methods are there?
Once one has decided on the thermal preservation of wood, various methods are available to be used depending on the type of infestation and the structural environment. Currently, only the hot air method is specified by DIN, only detailed studies have been performed about their effectiveness. Hot air is generated by a fan-assisted gas or electric heater and is particularly suitable for large areas such as entire buildings, roof trusses or furniture in a heating chamber.
Although other alternative wood preservation procedures are not standardized, they represent a reasonable alternative to hot air depending on circumstances, especially if the infestation is on a small-scale. This involves completely wrapping exposed beams and furniture in electric blankets and heating them to the required temperature within a relatively short time. The infrared method is particularly suitable for massive structures such as walls, ceilings or floors, and thus also for controlling true dry rot. By means of infrared radiation, also referred to as heat radiation, molecules are excited to vibrate; the method can be focused on defined areas.
Alternative wood preservation with electro-physical methods (microwave)
One variant in alternative wood preservation is the heating of especially small and humid areas through microwaves. The advantage: The target temperature is reached much faster than in the case of other thermal wood preservation methods, and the total duration of remediation can thus be significantly reduced. However, there is a significant risk to nearby electronic equipment such as computers, phones, etc., as these can be damaged or destroyed by microwaves, and people should keep their distance as well. Because microwaves heat water molecules, it is necessary that the components to be treated are moist, which is not always so in the case of brickwork. Moreover, the required temperatures are only achieved with great effort. In addition, an object exposed to microwaves is always heated from the inside out, which is not very beneficial, in particular in cases of infestation with insects. The latter are located in the outer sapwood so that before the heat reaches the outside, the wood core may threaten to overheat. In case of doubt, the infrared method is preferable as a „safe alternative“ to the microwave method.
For all thermal wood preservation methods: The heating must be constantly monitored by measurement technology in order to control the heaters according to the required framework conditions. This is the only way to guarantee the success of the measure.
For further information about the various thermal wood preservation methods, see the following links or call us: tel. +49 30 96535105-7.