Roof from PEFC Certified Wood (.uk)
Friday April 27, 2012
PEFC certified materials are being increasingly used throughout Europe for large-scale construction projects. A recent example is the use of PEFC certified wood for the roof of the new Tesco Express store in Dunfermline, Scotland.
In a departure from normal practice, the new Tesco Express store in Dunfermline has a curved wooden roof. This is a first for the UK retail organization. Usually, Tesco Express stores come as a prefabricated unit with a flat roof that is assembled on site. In the case of the new Dunfermline store, the local authorities responsible for delivering planning permission asked that the store have a curved roof to ensure that it blended in better with the local environment.
In light of this challenge, building contractors B&K Structures, who were responsible for the project, approached Donaldson Timber Engineering (DTE) with a request that they supply the roofing structure.
DTE was the first UK manufacturer of roof trusses and engineered floors to be PEFC certified. All DTE products are made using legal and sustainably sourced timber, making the company purveyors of one of the most environmentally-sound standard building materials.
The use of certified timber can significantly reduce the environmental impact of construction. Timber roof trusses, in particular, use 40-50% less timber than traditional cut roofs, which not only reduces their environmental impact, but makes them lighter as well as strong. PEFC certified timber roof trusses are an ideal roofing solution offering sustainability, speed, cost-effectiveness and design flexibility.
The roof trusses were prefabricated offsite at DTE's Buckhaven factory and then delivered to the site where they were lifted into place quickly and cleanly. Forty-four barrel-vaulted trusses with 14 metre spans, and two barrel-vaulted spandrel panels were lifted into position by crane, and braced with 22 x 100 PEFC certified timber. The spandrels were then lowered into place at both gable ends, creating a finished product straight away.
The building process began on the Monday, and the roof was wind proof and watertight by the following Friday. Although two weeks had been set aside in the planning for the roof, DTE was able to complete the roof in just one week. One of the key benefits of using certified timber roof trusses is the speed of construction: this project offered a clear demonstration of just how quickly the building process can be completed, even for a complex roof. This also resulted in savings of time and money for the contractor.
Managing Director of Donaldson Timber Engineering, Jonathan Fellingham said: "This was a brilliant project for us. It was an unusual contract because a curved roof is not something you see very often, so it was incredibly interesting to work on. There were a number of challenging aspects to the job, such as the curved trusses and spandrels; and the wide spans of the trusses, but the beauty of timber trusses is that they can be precision engineered to meet very specific design needs."