Cross Laminated Timber (CLT)
|Cross-laminated timber (CLT) is one of the most significant types of engineered wood product recently developed for structural applications. |
Constructed from layers of timber glued together in opposing directions, it can also be constructed with recycled timber – adding to its inherent environmental credentials. 
Arriving onsite with factory installed insulation, power and data networks, trim and even windows, the use of CLT can reduce on-site construction time significantly, minimising exposure to damage and delays from weather. 
How does it work?
CLT is typically made from either spruce, pine, or larch, which is planed for thickness then kiln-dried to reduce moisture content.
The conditioned timber is then stacked into layers, known as ‘lamellas’, at 90 degrees to the layer below, then glued together. They are then hydraulically, or vacuum pressed together to create high-strength structural panels.
The gluing of longitudinal and transverse layers reduces the movement of wood and allows it to span in two directions like concrete. This structural integrity gives it the potential as the primary structural system, for use in either single story or high-rise buildings.
Coming in many thicknesses and being relatively light weight, CLT panels are highly versatile, easing total building weight and leading to a reduction in foundation requirements (read: cost!). 
But CLT is much more than simply a structural building material – it is an opportunity to evolve building design and construction, making it easier to create elegant buildings that are efficiently built, and environmentally responsible. 
- Reduced loading on foundations allowing lighter weight foundations
- Impressive acoustic performance
- Fire safety potential – with 30-, 60-, or 90-minute fire resistance possible
- Manufacturing offsite leads to manufacturing precision
- Improved project delivery timescales
- Cost & time certainty
- Good carbon sink
References: Wigo Group. (n.d) Prefab CLT panels: the most advantageous construction material for modern timber buildings  Davies, A. (2018) Modern Methods of Construction: A forward-thinking solution to the housing crisis?  Timber Lab Solutions (2021). Cross Laminated Timber Technical Brochure
For more information about CLT products in New Zealand, see: