This invention, hereinafter referred to as 'Product', is a sandwich-insulated log and squared timber, i.e., a sandwich-type insulated construction element. This construction element is in its essence mostly applicable for the construction of wooden houses and other wooden buildings.

The purpose of this Product is to provide a sandwich-insulated log that meets all modern requirements, has great insulation qualities, is highly sound-proof, hydrophobic, and moisture resistant, has good fire resistance properties, good structural strength (the insulation has the required tear, compressive and tensile strength), is chemically stable, recyclable, and perfectly safe for people as well as the environment.

Although the solid wood log houses that our forefathers built are environment-friendly, their insulation qualities do not meet modern requirements. In addition, old log walls are not wind-resistant at the joints and since rough logs are not moisture resistant, the walls are not stable either. If the temperature outside the building is below zero and inside above zero, then the dew-point is inevitably inside the walls in case of all house types and even in case of insulated houses. Since the insulation material of any house type is not usually vapour-proof, meaning that since there normally is some capillarity, air humidity is able to move inside the insulation and water vapour will inevitably condense at the dew-point. This means that the condensed vapour, i.e., water, stays inside the walls, particularly inside the insulation material, creating favourable growth conditions for micro-organisms, above all moulds and rots. Since Styrofoam insulation materials have some capillarity and are not chemically stable, they can, over time, emit unfavourable and toxic substances to the room. In addition, Styrofoam is a flammable material. As woollen insulation layers absorb water, they damage the wood in the long run. And there are also many other common problems.

Not only does this Product eliminate all the aforementioned shortcomings, it is also an easily installable construction material with a sound interior and exterior finish, a highly efficient construction material for wooden houses or other wooden buildings, meeting the ever-increasing high modern requirements. It has an extremely efficient and particular finish, which is done via vacuum impregnation using hot linseed oil with added UV-protection, colour pigments, repellents, and other required or desired substances. If the area in which the wood is to be installed is highly moist, the wood is previously deep-impregnated with salts. This ensures a fully protected, natural, perfectly human and nature friendly construction material that will last for decades.