Benoy's Beehive gets the Finnish hot wood treatment
Benoy has claimed an environmentally friendly first in the UK by pioneering the use of ThermoWood - a heat-treated wood based on a method used by the Vikings more than 1,000 years ago - on a new £650,000 retail building in Cambridge. The treatment uses no chemicals and results in a harder, more stable, less absorbent and deeply coloured wood with a markedly greater resistance to rot and mould.
Project architect Gary Thomason said: 'We wanted to do something different and try to make a building for the client which is more environmentally aware. The process doesn't use chemicals, is natural and affects the wood right through to its core, unlike tannelising.'
The process involves treating wood at temperatures of around 190-240degreesC for two to four hours in an oxygen-free chamber so it does not burn.
That breaks up cellulose chains so decay-causing bacteria cannot feed on the wood - in a single day the wood 'ages' by 200 years.
However, the company which has patented the process, Finnforest, admits that its downside is that bending, tensile and compressive strength is weaker - it recommends using the material for external wall panels and cladding, flooring, furniture, windows and doors.
Benoy is using it as a rainscreen on the new 600m 2'gateway' building it has submitted for planning permission to be built for British Land at the Beehive retail centre in Cambridge. The building is constructed from curved glulam timber and roofed in prepatinated copper with a main entrance of Planar glazing - and featuring Thermowood-clad walls.
Finnforest started producing the material five years ago in Finland and says the market potential is 'huge'. The company is rapidly expanding its production facilities in Finland to cope with expected demand.
Cambridge City Council rules on the planning application on 2 May.