Leverkusen, Germany -- While typical Scandinavian wooden houses are highly attractive, heat insulation can be an issue in such constructions. And Norway now has new energy conservation legislation which aims for a substantial reduction in energy consumption.
Local company MjosCon AS -- a subsidiary of Mjosplast AS based in Moelv, Norway -- has been working with Bayer MaterialScience to cut the heat escape through gaps between the timbers in wooden constructions.
Bayer MaterialScience's Nordic BaySystems polyurethane systems house in Otterup, Denmark, has helped the construction firm develop a solution for the year-round usage of wooden houses -- based on rigid PU foam, which BMS says "has the highest insulating capacity of any material on the market." To achieve the same level of heat insulation with conventional insulating materials, the walls would have to be thicker, and windows smaller, reducing living space and giving less natural light.
In the MjosCon system, two wooden beams are placed in a mould and the space between them is filled with a liquid polyurethane system. The mould is then sealed and the composite cured at around 45ºC.
BMS says the polyurethane "adheres extremely well to the wood substrate," so that the composite is mechanically stable. Addition of the 60-mm-thick layer of polyurethane rigid foam gives a composite timber measuring 198 by 47 mm.
This technology significantly improves heat insulation, and, said Bayer, "most importantly, thermal bridges between the interior space and the exterior are prevented."