From Tree to Glulam Member
The volume, automation and vertical integration of ASH’s SUPAPOST and SUPABEAM mean that these glulam posts and laminated timber beams will be available at an unrivalled cost and delivery time, with strong aesthetic appeal.
Why Choose Glulam?
Sustainable timber is the building material of the 21st century. Glue laminated timber is the preferred choice for mass timber construction for the following reasons:
The construction sector is said to be responsible for 18.1% of Australias carbon emissions. When this type of wood is used to replace building materials of high embodied energy, such as concrete and steel, it can help beat Australia’s greenhouse gas emissions targets.
This choice of timber is also lighter in weight, which translates to cost, solution and time benefits. Every cubic metre of our glulam wood is better than carbon neutral with approximately 320 kg of stored carbon as opposed to a negative embodied energy output in alternate products.
Timber can be cut, drilled, docked or worked easily on site and can be installed by regular trades. What’s more, timber is aesthetically appealing and creates a more inviting and relaxing workplace. A structure with expressed timber elements is both a point of difference and a competitive advantage.
Glulam or Cross Laminated Timber? Which is Better?
Glulam, GLH or GLT offer advantages over Cross Laminated Timber (CLT) in many applications yet compliments CLT in others. Together, they make a great team.
A glue laminated timber beam and post ‘grid’ offers open plan design options for applications such as offices and commercial buildings. In these scenarios, laminated hardwood beams and posts are used as supporting grids that incorporate CLT or glulam floor members. The open plan design of a grid system allows partition walls to be constructed and/or removed when required and, best of all, is cheaper to construct because it has less volume of timber. This can be a desirable alternative to the static ‘honeycomb’ system most employed in CLT systems where large, cross-laminated timber panels become load-bearing walls and are fixed in position to make a closed-plan design.
Our laminated timber beams and posts are constructed using Australian hardwood. This adds to a building’s beauty and strength. They have linear, quarter-sawn grain for stability, no knots, and are naturally blonde in colour to deliver a stunning appearance. They can be painted or stained to match your design requirements, or they can simply be used as strong, structural members, hidden behind plasterboard if you choose to only take advantage of their strength.
Strength and Weight
The SUPAPOST and SUPABEAM range of glulam members have some of the strongest strength characteristics of all ‘mass-timber’ options worldwide. They are made using the sustainably harvested, Australian hardwood – Victorian ash.
Having one of the best strength to weight ratios of all known hardwoods, these glue laminated timber members exceed strength characteristics of GL45 (as according to EN14080:2013 – Timber structures. Glued laminated timber and glued solid timber). Or GL18s (as according to AS1720.1:2010 Timber Structures).
The strength to weight ratio of timber exceeds concrete and steel. When comparing beams of a similar strength, a glulam member is four-fifths the weight of steel and one-sixth the weight of concrete.
The strength rating of each timber species is determined by its known strength properties, fibrous makeup and by limiting the number of inherent strength weakening characteristics such as gum vein and/or gum pockets. The glue laminating process of SUPAPOST and SUPABEAM counterbalances these characteristics and strengthens its performance, thus reducing the ‘bell curve’ in destructive tests.
SUPABEAM is created using regrowth hardwood from third party audited, certified sustainable resources. A detailed pack of sustainability information can be viewed here.
ASH has the largest and most advanced hardwood glue-laminated timber line in Australia. We are in the process of adding to this already super-efficient line so that we can produce 100% of the mass-timber members in one automated process. This investment will result in further cost savings for the construction sector and the completion date is expected to be approximately Feb 2019. Until then, ASH can supply a less comprehensive range of glulam laminated hardwood beams direct, or in conjunction with our supply chain for structural members outside of our current ability.
Furthermore, timber mid-rise construction is proven to not only increase construction speed but it is said to save between 5% and 25% of building costs. When deducting these percentages from a multi-million dollar project and allowing tenants/purchasers to move in earlier, the result is a more profitable project with a quicker return on investment!
Large timber sections have known and calculable performance during fire and maintain structural integrity when exposed to heat. (See AS1720.4 Fire resistance for structural adequacy of timber members, which provides the method of calculation).
Concrete and steel can lose their structural integrity quicker than massive-timber. It is a popular misconception that a timber building is at greater risk of fire than one constructed of concrete or steel. This is likely due to our personal experiences starting a domestic fire. Many of us draw our conclusion from burning small sections of firewood – but have you ever placed a large log onto a campfire and noticed that it struggles to ignite and burn? This is the benefit of massive-timber. As massive-timber is exposed to fire, it creates a level of char on the surface while maintaining strength behind this ‘char layer’.
SUPAPOST and SUPABEAM have a calculable char rate of 0.586mm per minute. Allowing for the required 7.5mm transition zone (as required per AS1720.4) this translates to approximately 25mm per 30 minutes, 43mm per 60 minutes or 78mm per 120 minutes. The strength of timber beyond this char layer maintains structural integrity. This design approach is used to protect the structural timber member by providing a sacrificial layer to the required end section for the char level or time frame desired.
For example, if a 300mm x 300mm structural post is required to achieve a FRL of 30min, the post could be supplied in one of the following options:
- an excess of 25mm on each fire-exposed surface of the post. Becoming 350 x 350mm. Or
- 300 x 300 + one layer of fire proof plasterboard. Or
- Using a ‘Performance Solution’.
Designing for fire
For more detail around how to design for fire, follow this link.
Above: Copy of diagrams from AS1720.4 showing the charring effect of fire. Note: The ‘Calculated effective depth of charring dc’ is equal to the ‘Calculated notional charring line’ (e.g. 30mins x 0.586 = 17.7mm) plus 7.5mm = 25.1mm
Safety & Noise
Working with timber is both safer and quieter than working with concrete and steel, plus many of the benefits will be appreciated by your neighbours. No concrete and steel work means less hot works, noise, cranes, truck deliveries, construction workers on site, and minimised risk with high voltage electricity. Scaffolding can also be installed on floor panels before lifting, enabling speedy installation. These office buildings can be constructed at a rate in excess of one floor per week – so trades spend less time in each other’s way.
The material cost is only one part of the value proposition. Installation time, labour, crane hire, scaffolding, etc. are all part of the equation. The following link is a detailed cost comparison for a 7 story building – comparing concrete to glue laminated timber construction. In this detailed comparison, timber construction saves 13.6%. Wood Solutions – Rethink Office Construction Report
Continue the flow of design
People have had a connection with wood since the evolution of humankind. Timber is both the most ancient of building materials and at the forefront of new-age construction. Exposed timber elements invoke our instinctive, primal connection to nature. They bring the outside in. They are warm and inviting. A new study suggests timber structures reduce blood pressure and stress as well as bringing comfort. Why not express the structural elements and take advantage of both the visual appeal and structural strength?