Something is afoot in the land of the log cabin. To help boost its timber exports, Finland has developed a range of high-tech wooden products and built striking structures to showcase them.
The Finns are mad about wood. They write with wooden pens, eat off wooden plates and open their beers with wooden bottle openers. You even see people carrying wooden briefcases.

Surprisingly, though, in a country that is 85% forest, the tradition of making wooden buildings has all but died out. A series of devastating fires earlier this century prompted stricter fire regulations that favoured materials such as brick and concrete. For years, saunas were just about the only timber structures built.

But now Finland is once again beginning to turn trees into buildings. The motivation is economic: realising that there is money to be made from its prime natural resource, the government is encouraging the timber industry to develop high-tech construction products.

“The tide has changed and we are convinced that wood is an excellent material for anything,” says Pekka Patosaari, forestry and environment councillor at the Finnish Embassy in London. “We are realising we should develop value-added products. It’s a question of innovation.”

To help kick-start the industry, the government has rewritten its fire regulations to accommodate timber buildings and encouraged a wave of showcase projects around the country.

You name it; the Finns are doing it in wood. The most improbable building is the Sibelius Hall in Lahti (31 March).

This is a concert venue and conference centre made almost entirely from plywood, glulam beams and pine, but the Finns have also knocked up a wooden fire station, a plywood university building and a whole series of spruce highway bridges.

However, the structures have more than novelty value – the technology that goes into them is cutting edge. Deep in the forest, a couple of hours from Helsinki, timber giant Koskisen has combined its entire supply chain in a single factory. “This company has the largest chain of value-adding anywhere in Europe,” says Juha Miettinen, Koskisen’s building products manager. “We have achieved integration of the supply chain from forest to house.”

In simple terms, Koskisen puts trees in one end of its factory and takes a range of completed products, including kits for houses, from the other. In one part of the 34 ha complex, the company produces timber-framed homes for the self-build market. A CAD operative feeds the buyers’ chosen design into a computer, which draws up the required frame.

The CAD file is then e-mailed to the factory, which automatically chops up timber planks to length, cuts rebates and angled joints and marks each component with a digital code.

The entire process takes 40 minutes a house, works to a tolerance of half a millimetre and requires two operatives. The company claims its production line is so efficient that only 1.5% of timber is wasted.

Koskisen is moving into the European market, starting with Germany, where it claims it can put up houses 80% faster than anyone else and aims to double the size of its local operation each year for the next 10 years.

At another factory near Lahti, plywood manufacturer Schauman Wood is developing ways of using its products as a structural material. Last year, it completed its showpiece: a hamburger restaurant at the Linnanmäki amusement park in Helsinki made almost entirely of plywood.

A 17 m diameter dome constructed entirely of Wisa-Birch plywood tops the 500 m2 building. Radial struts made of bonded plywood are locked together with glulam rings to form a rigid structure that is clad in 12 mm plywood.

And the company claims that the burger bar is just a start. “This is a small model. We are trying to reach spans of 100 m,” says Schauman Wood’s Arto Juvonen.

But despite such demonstrations of virtuosity in timber, companies such as Schauman Wood realise that they have their work cut out to make significant inroads into overseas markets, not least because of fire regulations.

“Fire regulations in Finland and other countries have been the biggest hindrance to using wooden products in buildings,” says Eija Simonen, Schauman Wood’s environment manager.

“For example, in Britain, none of our products meets class 0 [the regulation covering how materials must resist the spread of fire]. But regulations are changing in Europe.

“In Finland, we have changed our fire regulations to performance-based fire regulations.”

Under performance-based regulations, fire safety specialists assess building plans on a case-by-case basis. They look at the solutions architects have used to remove fire risk, rather than only checking which materials have been used. Sophisticated computer modelling is used to predict how structures respond to fire, so any structural solution and combination of materials can be considered.

At the Sibelius Hall, for example, specialists gave the designers approval to build the entire building out of wood, with the exception of the fire escapes, which they asked to be made of concrete.

The Finns are devoting a lot of energy to fighting the perception that wood is a high fire-risk. They concede that wood is poor at preventing the spread of fire, but claim that it is extremely good at resisting it.

Vierumaen Teollisuus, a major producer of glulam beams, says structures made from its products withstand fire just as well as steel.

“People normally think that glulam is not good for the fire situation, but it’s good against fire,” said Vierumaen Teollisuus director Pekka Kopra. “It’s a very safe material. If there’s a fire in the building it still takes the load.”

Vierumaen Teollisuus prefabricates glulam beams at a number of high-tech plants in southern Finland. The company supplied the structural glulam beams for the Sibelius Hall, but its products are now increasingly being used for exposed structures such as bridges. These applications are designed to prove that wood can withstand the elements.

Wood’s tendency to rot is one of the material’s great drawbacks and the environmentally aware Finns are reluctant to use great quantities of sealants, which are often toxic or polluting. Instead, they are developing eco-friendly ways of treating wood.

Ikipuu, another timber firm, is manufacturing ThermoWood, a heat-treated pine suitable for external cladding. Ikipuu claims the product is resistant to rot and retains a high degree of dimensional stability. The process involves heating wood to between 180°C and 230°C degrees for up to 24 hours, reducing the wood’s ability to absorb water, enhancing heat-insulation properties and cutting moisture content.

“The treatment breaks up cellulose chains so that decay-causing bacteria cannot feed on the wood,” says Ikipuu managing director Petri Rajasuo. “The wood ages 200 years in 24 hours at the same time that resin and a lot of water are expelled.”

The company is also involved in a peculiarly Finnish construction project to demonstrate its products’ water resistance – a 50 m2 floating sauna moored off an island near Helsinki.

ThermoWood was also used as cladding on Finland’s pavilion at Expo 2000 in Hanover. And, if that didn’t convey Finland’s message in plain enough terms, the pavilion consisted of two wooden buildings with a forest between them.

Green wood

Despite what the Finns say, timber is never going to be the most suitable material for every job, but its sustainability credentials are unbeatable. Schauman Wood’s Eija Simonen says 80% of all materials the company consumes – including power and transportation – are renewable; oil and natural gas make up most of the rest. The company has reduced dust emissions by 90% over the past 10 years, and total waste has dropped 500% in the same period. The timber-milling process is practically waste-free – woodchip is recycled into chipboard and sawdust is burnt in the drying kilns.

The 40-second logger

It takes a Scots pine about 90 years to reach full maturity, but about 40 seconds to be turned into a pile of logs by the giant “Timberjack” machine. Operated by one person, each machine costs £300 000 and can operate in temperatures as low as –25°C. The Timberjack’s on-board computer sizes up each tree and works out the optimum way of sawing up the trunk. The machine then grips the tree in its powerful jaws, fells it and strips off all lateral branches, slicing the trunk into logs as it goes. It marks each log with spray paint according to the grade of timber (high, low or pulp) and automatically e-mails the sawmill to update the inventory. Finland, roughly the same size as the UK, has 85% forest cover, with birch, Scots pine and spruce the most common tree species. Each year, 55-60 million m3 of timber is harvested. The renewal rate is 80 million m3 a year, so the country grows more than it uses. Timber and timber products account for about 30% of Finland’s annual exports (Nokia, the telecommunications giant, accounts for 50%). The vast majority of forest is owned by private landowners, who sell exploitation rights to the large timber companies. Logging is carefully controlled by law to prevent over-exploitation, and all cleared areas must be either replanted or allowed to re-seed.