Engineered Timber Solutions for roof systems
An engineered timber roof solution designed by Metsä Wood was developed for East Shopping Centre, located on the site of a former bus depot in East London and situated in the heart of Green Street. The centre’s shops are arranged along both sides of a central pedestrian street. The central aisle is covered by a pitched steel roof structure either side of which is a large flat roofed area above the shops.
Wren Architecture and Design approached Metsä Wood originally specifying Finnjoist® I-beams to support the flat roofed section. However, in the original design, the steel used to brace the structure would have clashed with the joists making construction of the roof expensive and time consuming.
As a cheaper, more practical alternative, Metsä Wood put forward an engineered timber solution using Kerto®, a laminated veneer lumber (LVL) product used in all types of construction. Kerto is produced from 3mm thick rotary-peeled softwood veneers that are glued together to form a continuous sheet which makes it incredibly strong and dimensionally stable.The Kerto product range includes both Kerto-S and Kerto-Q, both of which were used for the roof; Kerto-S for the joists and Kerto-Q panels to form the rigid roof deck. The use of Kerto, provided the necessary lateral stability to the structure and avoided the need for steel bracing.
Lee Dyball from Wren Architecture and Design stated “Taking out the steel braces enabled us to standardise the detailing across the flat roof element of the building,. We have subsequently been able to use the green credentials of this system to improve the overall environmental standard of the project”
The Kerto was supplied through Donaldson Timber Engineering (DTE), one of Metsä Wood distributors. They supplied a total of 1,710m2 Kerto-S and 1,200m2 Kerto-Q.
Luke Roberts, General Manager at DTE commented “Metsä’s design enabled DTE to simply cut and supply material to site, the accuracy of the design meant that this considerable Kerto LVL job was delivered and installed without any issues!”
Engineered wood products can provide an excellent, cost effective structural solution. When compared with sawn timber, engineered wood products can be longer, wider and deeper. Their performance is also more predictable, so their design strength can be higher. When compared to steel and concrete, engineered timber solutions have low embodied energy making them a clear and cost effective environmental favourite every time.