Alan Goodger, chairman of timber merchant/ importer JF Goodwillie Ltd, is enthusiastic about heat-treated timber and believes its use in the UK can only grow.
Two years ago his company was the first in the UK to import the wood from Finland. Timber agent John Hood tipped Mr Goodger off about the emergence of the product. A visit to Stellac’s Mikkeli plant followed in February 2000 and the wood was in the Waterlooville yard by the autumn.
Mr Hood admits he is still staggered by the wood’s performance. He has been in the industry for nearly 50 years and would not have believed it unless he had seen it. “It’s stable and stays stable,” he says.
Stellac’s two kilns can handle up to 50,000m3 a year. The process takes about 24 hours during which the wood is exposed to temperatures between 200-250 degrees Celsius. Moisture and resin are removed and the structure of the wood is changed.
Akin to hardwood
The softwood takes on a rich brown colour, more akin to hardwood. It also gains improved stability, durability, surface hardness and resistance to decay (even to the level of chemically treated timber, according to Stellac). Water absorption is also decreased and heat insulation increases. Crucially, the process involves no chemicals, so the wood gains added environmental credentials as well.
On the down side it can lose some strength properties and, like untreated wood, the colour weathers to grey.
Treatment levels
Different treatment levels are available depending on end uses – ‘D2’ is imported by Goodwillie’s and is guaranteed rot resistant for at least 10 years, though there is confidence in Stellac’s corner it could last 30-40 years. Several test planks were put on the roof of Goodwillie’s yard two years ago and are still reading a moisture content of just over 5%.
Goodwillie imports redwood but Stellac says the process is suitable for all types of timber, with spruce, pine, birch and aspen the species used the most.
Mr Goodger said one of the first applications for the wood was for a swimming pool roof. Shiplaps, cladding and especially decking are being sold from the yard.
In Finland it has been used for doors, window frames, stairs, high quality garden furniture, fencing, sauna interiors, kitchen utensils, sheds, flooring and even musical instruments. Buildings clad with the wood include the Finnish pavilion at the Expo 2000 World Fair in Hannover and the World Trade Centre, Amsterdam.
Too conservative
Mr Goodger admits he is surprised that other importers have been slow to adopt the product. “The trouble with the timber trade is it’s too conservative. You have had products that are more marketing than substance and purely geared for site practice. But this is, I think, a genuine advance in terms of timber technology and I have no doubt it will break into the established part of the trade.”
But he emphasises that heat-treated timber is a specialist item, a value-added ‘extra’ which makes up only a small part of the company’s trade.
Timber has so far been sold to “discerning” customers, often after specification by architects. “Most of it has gone out to the small builder and the man on the street but that will change because we are getting samples in all kinds of places.”
He believes the heat-treated timber has great potential as cladding as it is light, durable and both cheaper and more environmentally sustainable than cedar.
Aversion to CCA
Proposed restrictions in the use of CCA were not the motivation for dealing in heat-treated timber, but Mr Goodger says he has no love for the traditional treatment. “I will not have a CCA plant on the premises because I think they’re bad news. I stock a little bit of CCA-treated wood and do some for certain customer requirements. It’s a reluctant necessity.”
Mr Hood believes heat treatment will “seriously” take-off when environmentalists get behind it but he cautions against a big marketing push, as steady supply channels and knowledge about the product need to be built up.
He agrees that heat-treated wood will remain an “extra” for higher value items, and that the bulk of merchanting timber will continue to be for carcassing and fencing.
And how will it affect timber treatment companies?
“I do not think this will significantly affect their market. I think this is an additional option,” says Mr Goodger. “Traditional treatment plants can cope with virtually any combination of dimensions, which will never be the case with the kiln.”
But he believes heat-treated wood is here to stay.
“As supplies of hardwood dry up in Brazil and the Far East, there is going to be increased opportunity.”
