Glued Laminated Timber, better known as Glulam, is created by gluing layers of timber together with a durable adhesive. Cabinco uses glulam timbers in the structural upright posts of our School Shelters and gazebos, and as standard in the wall log of our Eco School Buildings, as well as extensively in the roof structures of our larger buildings.
This technique has been used for over 100 years to create large strong structural members from smaller logs. These pieces, when combined, have greater strength and design flexibility than a solid log. As a result they are popular with architects, especially when creating spaces with visible structural elements, especially imaginative curves and large spans.
Laminated timbers have many advantages over steel and concrete, not just for appearance, but substantially reduced weight and greater potential for longer spans, heavier loads and unusual shapes. A structural steel beam, for example, may be 20% heavier, and a concrete bean 600% heavier than an equivalent glulam beam.
As a function of their engineered nature, glulam beams will also be less affected by knots and other perceived natural “defects”, which can be important: particularly in timbers used for decorative structures, such as school gazebos or shelters, where appearance is a major consideration.
By using laminated timbers in your school shelter, you will also have a timber which is considerably less likely to crack or split. Cracks and splits in school gazebo structures can an invitation to curious little fingers and result in splinters for pupils. They may also increase susceptibility to weather damage for the structure itself. Laminated timbers avoid these risks and increase the longevity of the shelter and consequently its value for money.
A small percentage of materials used in building construction can be recycled but timber is the only renewable building material. The planting rates in Scandinavia are controlled to ensure growth exceeds harvested quantities. In these countries there is more standing timber than at any time since the ice age. This cycle of felling and planting is very beneficial to the atmosphere as it is only during growth that a tree absorbs CO² and gives off vital oxygen. Once a tree is mature this process virtually stops. (www.glulam.co.uk)
Glulam elements make far greater use of smaller logs, which are harvested from commercial plantations managed and replanted to ensure long term viability. Use of small softwood logs in engineered timber elements such as glulam reduces consumption of older growth solid sawn timbers, especially hardwoods.
Glulam beams not only have a far better strength to weight ratio than “conventional” steel or concrete elements; they also consume considerably less energy, and generate an order of magnitude fewer pollutant by-products during production. For comparable section (in terms of structural performance) concrete and steel beams require 5 and 6 times the energy cost, respectively, to produce.
Glulam’s high strength to weight ratio facilitates longer clear spans, meaning that our school and nursery buildings can be wider, to provide greater open spaces for school halls, visitor centres and bright open offices.
In conclusion by choosing an outdoor classroom, shelter, or school building which incorporates glulam members in its design, you have a stronger more durable product with increased sustainability, lower embedded energy, and providing over all greater value for money.