Industrially produced log gives centuries old log construction a makeover

Log construction has long traditions in Finland based on the suitability of the excellent raw material, the skills of the craftsmen, and log construction for the demanding Finnish climate. New industrial log materials, manufacturing technology and indoor air requirements have increased interest in log construction. Finland is the world leader in industrial log construction. It produces an increasing amount of log buildings for the Asian, Central European and Nordic markets.

There are a wide range of potential uses for industrial log, which has allowed it to conquer markets both in private housing construction and in public construction such as schools and day-care centres. Industrial log presents designers and architects with new opportunities as a material, which has given them a newfound interest in log construction. While log was previously primarily used for building recreational buildings, it is increasingly used in buildings intended for continuous use.

The Pölkky Group from Kuusamo, Finland is a 50-year old, diversified Finnish family company that operates a sawmill, produces log houses and owns a hydro power plant. This group based in north-eastern Finland has an annual turnover of EUR 186 million and employs a total of 430 people. This article covers the new arrival of log house production, which is based on the new industrial development of immovable glued laminated log and the introduction of environmental factors to construction that are fuelling wood construction.

Industrially produced log revives log construction

According to Jouko Virranniemi, Chairman of the Board of Kuusamo Hirsitalot Oy, which is part of the Pölkky Group, the new strength of log construction on the market is based on two factors: – Pölkky’s new sag-free Log is  based on cross-glued lamellas on both sides of the log. The industrially manufactured glued laminated log doesn’t compress and it provides opportunities for design and architecture for modern wood construction. The share of log construction has grown in single-family homes and in public construction.

– Public procurement law already allows for the use of wood, and public construction should make greater use of these possibilities. There should be a stronger focus on environmental factors in the bidding process in particular, following the example of Central Europe where there is a strong desire to openly favour local materials and local businesses. Virranniemi is of the opinion that consumers should be given a stronger voice in the public procurement process.

– When the discussion in Finland turns to the problems with mould and indoor air quality in schools and daycare centres for example, bolder solutions should be advanced with the construction of new buildings from breathable wood.

– There is now a need for more wood construction experts. Modern glued log requires its own expertise in structural design, architecture and construction. Glued laminated log  is a stable construction component as such, and its use results in cost savings when compared to component construction because the log surface is ready as is.
Virranniemi is pleased with the revised fire regulations, which allow solid timber to be left visible in buildings. – We were forced to ruin many log houses by covering the log walls with plasterboard, even though the building had sprinklers. Fortunately, we can now make log houses that look like log houses.

Virranniemi acknowledges the old-fashioned reputation of log construction, but believes the new generation of glued log will find its place in modern wood construction. – We have fabulous architectural examples of new log construction because the non-compressible nature of the timber offers unlimited possibilities for different types of construction. Log is no longer for summer cabins and recreational buildings. Rather, it is used for more and more homes meant for year-around residence and public buildings such as schools and day-care centres.

Log construction can help combat climate change

Traditionally, log houses have been exported to the Russian, Japanese, Central European and Nordic markets. “Russian exports have of course dropped from their best years due to the sanctions. Exports now focus on the Nordic countries and Central Europe. The most important export product is now prefabricated log houses, which include a timber frame and floor and roof materials.

– The competitiveness of log construction is based on prefabrication, the longevity of the buildings and the preservation of their value. Log construction is an environmentally friendly option that should be promoted by public authorities both in public construction and with tax incentives. The funding of green construction, which is in its infancy, is another good way to promote wood construction as part of the solution for combating climate change.

Virranniemi suggests that the value of wood in building material is highlighted in the midst of natural disasters and as non-renewable resources dwindle. Wood construction is by far the most environmentally friendly option, and it is also suitable for urban construction.

– We have completed large sites where the quality and price of log construction have been our strong point. We do not merely export log as a material, but also log construction solutions, expertise, and wood architecture.

Also, Virranniemi, who is closely involved in sawmill operations, sees strong growth in the global construction market ahead and an increase in the share of wood as other non-renewable raw materials become hard to replenish. “Finnish wood is the best in the world and thus best suited for high-quality end use. For example, exports to China have multiplied in recent years, and the increase is based on high-quality spruce used for manufacturing children’s furniture, among other things. Availability in China will improve in parallel with improved logistics once rail transports become available in addition to the currently used shipping.

– Selling Finnish wood in foreign countries requires a competent consultant who is able to tell the target countries about the potential uses and to find the right high-value end use market for it.

According to Virranniemi, high-quality wood is facing considerable competition from decorative panels that are not actually wood but instead cheap materials that imitate wood. – In high-quality construction, wood is gaining popularity in interior decoration and garden construction, and the wood industry must be able to meet the increased demand with good products.

Log construction enables modern architecture

According to Virranniemi, collaboration with local market-oriented designers and architects is the goal in exports to Central Europe. – We need to know the construction regulations of each export country, of course, but we also need to know what customers like. We cannot manufacture ready-made products for a different market without the cooperation of local people.

– In Central Europe, alpine and tourist construction an interesting sector for us in addition to the area’s normal building construction. In Asia, namely China and Japan, the health benefits and environmental impacts of wood are appreciated. Chinese industry, for example, is undergoing an incredibly rapid change from environmentally polluting practices to a cleaner approach.

Virranniemi believes that there will be fierce competition over coniferous wood from the northern coniferous forest zone in future as it is only produced in Finland, Sweden and Russia. – Our products are trusted because Finnish sustainable forestry has a good reputation. Half of the EU’s strictly protected forests are in Finland, which will ensure sustainable harvesting in future as well. Finnish wood construction has earned its positive image with raw material that comes from renewable forests.

This article is part of a series by Markku Laukkanen and Mikko Viljakainen. The series presents a variety of best practices and trends in the Finnish wood industry. The aim is to spread information about best practices and solutions in the Finnish wood industry to increase its competitiveness and make Finnish expertise more widely known. The articles will be published in Finnish and in English. They will be made freely available for use as source material and for publication as they are. The articles will be distributed as Puuinfo newsletters and will also be published on the puuinfo.fi and woodproducts.fi websites. The article series is funded by the Ministry of the Environment’s Wood Construction Operational Program.