BUILDING STRUCTURES FROM HOMEGROWN SPRUCE

Spruce is the most widely available softwood in Wales but its use in timber buildings is limited at present because of its rapid growth in our mild, wet climate. A partnership involving the Welsh School of Architecture (WSA), Bangor University and Coed Cymru is investigating ways of manufacturing frames from machine graded spruce which has achieved the strength classification C16. This material is widely available and is used in general carpentry and repairs but most new timber frames use imported C24 softwood from colder climates.

The only limitation of the home-grown material is its tendency to twist as it dries. This can be overcome by lamination into compound beams and this option is being explored but the most promising results have been obtained by box beams which are simpler and cheaper to make than conventional laminates. Elements of this work have been contracted to Cowley Timberwork.

Meanwhile the WSA team have identified a whole building system for rural housing which can use these box beams. It is hoped that this will eventually form the basis of an affordable housing system which can include self build but in the first instance some simpler structures will be built later this year to test the basic system.

The project has been funded by the Countryside Council for Wales and Wales Forest Business Partnership. Models and drawings will be shown on a CALU event later in the year.