The consensus among Finnish timber product manufacturers, architects and timber trade bodies is that there is a massive potential for increasing timber’s use in construction.
Finland’s forests are now 90% certified, while its share of EU sawn softwood production is 19%, beaten only by Germany and Sweden at 21% each. In Stora Enso, UPM-Kymmene and Metsäliitto (incorporating Finnforest), it has some of the biggest forest industry firms in Europe.
Wood Focus Finland (created in 2000 by the merger of the Finnish Timber Council and Finnish Wood Research Ltd) hopes by 2010 that wood will be Europe’s leading material in building systems solutions and high quality home and office furnishings.
But, as Wood Focus’ project manager Petri Heino said, there is still much work to be done. ‘Timber has to be a price competitive way to build. The only way to achieve this on a large scale is to standardise activities. We need to standardise the length of the stud.’
‘Other parts of the wall and the floor would be standardised so that the industry does not have to produce tens of different dimensions. This creates lots of advantages in production and logistics.’
Mr Heino said such timber can be processed in a normal sawmill and delivered by the normal route. But he admits standardisation is still a long way off.
It is no good timber homes being 30% more expensive than concrete/brick and block – they need to be the same price or cheaper, he said.
The increasing recognition of timber’s environmental credentials is a boost for the material. Already, 21.9 million ha of Finnish forest are PEFC-certified under the Finnish Forest Certification Scheme.
Despite Finland’s affinity with wood construction it has only recently been given a boost by changes to building regulations.
After the burning down of the former wooden Finnish capital in 1867, wooden structures were restricted to two storeys high. Concrete has benefited in the past few decades, especially in multi-storey apartment blocks.
In 1995 building regulations were changed to allow the construction of timber buildings up to four storeys. This has led to increased confidence in building with wood, including some innovative public buildings.
In Sweden there are plans for an eight-storey wooden structure and some in the industry believe regulations will be changed further to remove all height limits.
Pekka Heikkinen, architect at the Helsinki University of Technology, said: ‘It’s the simple and most economic way of building a house. The use of more wood will be the feature in the next 20 years. It stabilises the moisture content inside the house, giving better inside air, and it’s the only building material which is renewable.’
Use of glulam and LVL has resulted in some innovative projects in the past few years including the Sibelius Hall, Lahti, and the Pohjola Stadium in Vantaa, where the main LVL beams are said to have nine times the tension strength of concrete. A plethora of timber schools and bridges have used glulam.
One of the largest glulam producers in Finland is Vierumäen Teollisuus, founded in 1946. It has manufactured the product since 1974, playing a pioneering role in its development. Today the company’s annual production of laminated products is 100,000m³, as well as 555,000m³ of sawn timber, 100,000m³ of other processed products including planed and impregnated timber and 80,000m³ of poles and piles.
Its products are used in sports halls, libraries, supermarkets, the Sibelius Hall, industrial premises, bridges (including the world’s first wooden highway bridge), apartment blocks and single-family homes.
Director Pekka Kopra said glulam’s big benefits as a ‘relaxed’ construction material include lack of movement in humidity and precise, lightweight components with the capability for exceptionally long spans.
About 70% of the company’s products are exported to countries including Japan, (glulam frame homes), France and to a lesser extent Germany. Its Novalam site is billed as the ‘most modern’ glulam facility in Scandinavia, and produces mostly for the export market.
Mr Heino at Wood Focus admits glulam’s use in the UK is still small, in part down to lack of knowledge among architects, but he believes there is big potential.
Finland has also seen the construction of experimental three-storey social housing in Helsinki. Mr Heikkinen said not only did the apartments have superior aesthetics, they also achieved fire safety standards that were higher than the equivalent in concrete.
Acclaimed as some of the best looking timber homes around are the three-storey terraced houses and four-storey apartment blocks in Lahti, built using a Platform frame system – and they certainly stand out among the surrounding concrete apartment blocks.
Architect Pauli Lindström said the sound insulation system of the three-bedroom flats – made of parquet flooring, chipboard, plywood and wool insulation – is better than concrete.
But he suggests very few of the timber homes in Finland are being manufactured in mass production prefab/modular factories operated by the likes of Westbury and Stewart Milne in the UK.
Timber construction is also popular for building schools in Finland, such as the £3.7m Metsola School which won the City of Helsinki’s building project of the year in 1991. Degerö School, also in Helsinki, has exposed beams and plywood panels creating an attractive, warm environment.
This emphasis on timber creating a warm environment and improving indoor air quality is preached at UPM-Kymmene’s Research and Development Centre WISA, Lahti. It predicts timber frame’s increase will lead to greater use of plywood – and it speaks from some knowledge of the market. Schauman Wood, part of the UPM-Kymmene group, produces a range of the material, including general purpose WISA COMBI, and lining and panelling products WISA DECOR and WISA Panel and its 10 mills in Finland produce 850,000m³ a year.
The Lahti centre sees wood’s hygroscopic properties (the ability to absorb water from the air) as a key advantage in the construction sector. It maintains that wood reduces peak relative indoor humidity by 20-30%.
