Devon’s landscapes are often considered to be among the most beautiful and diverse in the country. From the wind-swept moors and steep river valleys of Dartmoor, rolling through the lush green hills of south Devon to the towns, estuaries and beaches along the sparkling coast, there is a timeless quality to this wonderful county. But it hasn’t always looked like this. In fact, it’s never stopped changing through thousands of years where human endeavours have marked the landscape. Mineral extraction, charcoal production and widespread signs of the progression of farming are evident across the land and, in the last few centuries, swathes of deep green commercial forestry have covered patches of the higher ground in response to a need for home grown timber. As the plantation forests are evolving and conservation is becoming a higher priority for land managers, there is a growing industry in sustainable building materials and, if managed correctly, Devon’s conifer plantations can be a source of top-quality timber.
Small scale, local supply chains are likely to be a vital component of our future rural economy and timber for construction is one of those that will play a part in tomorrow’s industrious rural landscape. Standing on a breezy ridge surrounded by organic farmland, overlooking the Dart as it heads seaward towards Totnes is a small-scale sawmill, operated by a team of three skilled sawyers. Dart Valley Timber has been on this site for 5 years and the owner, Zav Bowden, explained how he ‘saw’ an opportunity to build on his woodworking skills to become a supplier of local timber into the developing sustainable construction industry. The Totnes area has a long-standing reputation for ecologically responsible businesses, including many that network across the community. The Community Land Trust was set up under the ‘Transition Totnes’ banner to develop sustainable housing schemes in the area. This has simultaneously supported the development of other local businesses including architects and builders. Zav described how the latest batch of timber had been transported the short distance from two Woodland Trust sites on the eastern side of Dartmoor. Both Pullabrook Wood and Fingle Woods are developing a local reputation for high quality structural grade timber and, in this case, are supplying sawlogs for a new timber framed house.
Following the ‘local’ trail, the building was conceived by timber specialist architect, Al Tempest and will be erected by Terra Perma from Totnes who specialise in ecological building. Their construction projects embrace the use of natural materials and well insulated, low energy designs. The timber structure of this new sustainable house will also stand the test of time, as the milled timber is being quality tested by another Devon entrepreneur, Jim White of White Wood Management . With over ten years’ experience as a forester and timber supplier, Jim is also skilled in visual stress grading of sawn, structural elements. As the milled sections are converted from logs and stacked at the sawmill, he ensures the quality of the milled timber meets the structural stress grading requirements before it is delivered to site. While training a new member of his team, he described the basics of the process. “Before the timber leaves the sawmill, the whole batch will be approved for structural strength.” The method he uses is a skill applied to smaller batches that are destined for bespoke designs. “This is visual stress grading as opposed to the machine testing that is more suited to larger volumes of sawn timber that are sold through builders’ merchants. First, we use the grain tester. It’s a small needle that is dragged along the grain to check if it is straight enough”. It follows the microfibres along the sawn face of the beam and is used to check the grain doesn’t run off to the side.
“We may also need to do a ‘knot plot’ from time to time to make sure a particular timber is safe for structural use.” This is an estimate of the sectional area of knots inside a length of wood. While the knots themselves are strong, the grain around them can be deflected which may reduce strength. Sometimes these beams can be used in shorter lengths to avoid using a weaker section.
“A visual check of the end grain also helps to understand the strength of the timber”, Jim explained, “The sap wood is visible on the end grain. You can see the early-season wood, the vascular part of the tree,” and, pointing at the darker growth rings, “there is the slower growing, late-wood that provides the strength.”
The Dart Valley sawmill is an atmospheric place to work, while the sawmill is undercover, much of the loading and stacking area is exposed to the elements and, as a winter storm approaches, the aroma of fresh wood resin permeates the air. After a downpour has passed, a rainbow gives the signal for fair weather while the sound of trickling droplets echoes around the log piles. The view down the valley clears again and work in the yard carries on.
Over at the sawmill, Rowan prepares a log for milling on the band saw. He has an instinctive eye for what is straight and parallel and quickly rolls the log into place to make the most efficient cuts. “We need to minimise knots and wany edges to get the most value form the timber”, he said, “It’s very satisfying to know the logs haven’t come far and the timber will be used in a building just down the road. It’s only about 8 miles away.”
This is a perfect example of a sustainable local supply chain. From the conservation woodlands where the timber is grown, through the hands of the ecological forestry team, this top grade, carbon capturing product finds its way to a new, low energy, structure where it will stand for generations as a beacon of what can be done with the skills and knowledge right here in Devon. In a time of change, this beautiful county and its people have more to do but are setting out a view of the future industrial landscape of Devon.
by Matt Parkins