Structural materials

Key Features:

• Radiata pine LVL was prefabricated into curved (and twisted) ribs in Hunter’s factory in Nelson.
• These timber I-beams were joined, overlapped in layers, then screwed together as they were assembled on site by Hawkins Construction.
• The exceptionally light structure ultilises timber members only 316mm deep at 4.25m centres to span almost 30m.
• The weaving of the timber structure to create a timber net or ‘gridshell’ is recalled by the local hapu as a hinaki or Maori eel trap.

• Designed by Stora Enso, the development for the new school building had to overcome very tight space constraints and stringent sustainability policies in the London Area.
• Built entirely from cross-laminated timber (CLT)
• Being made to measure there is virtually no waste on site and because CLT is a structural product it is a total integrated structure.
• The sustainability policies in the London area were an incentive to building in wood and a scheme was developed for a building that met all the requirements for a school and 15% cheaper than other alternatives.
• Apart from the cost advantage and the fast construction, there is little or no shrinkage.

• Nelson Pine Industries Ltd manufacture laminated veneer lumber (LVL) from locally grown Pinus radiata, so it was natural this material was used to construct their new warehouse.
• The brief required a storage facility of 16,500 m2 to be designed as a showpiece for the use and functionality of LVL.
• The overall dimensions of the building are 128 x 64 m, with an eave of 10 m and an apex of 14 m.
• Double 64 m portal frames at 8 m centres span the long direction.
• The apex of each frame is supported on a longitudinal beam spanning 16 m between posts.
• All portals, beams, posts, purlins, girts and diagonal wall bracing are made up from the raw LVL billets manufactured on site.
• The 400 x 45 mm purlins and girts were cut from the basic billet size while the rafters and legs were built up from the basic billet using glued and nailed splices.
• The portal knee and apex gussets have been nail fixed only to give increased ductility.

Key Features:

• 11 shear walls are installed in the auditorium.
• Each LVL wall (6.7m high x 2.4m) contains approximately 22 sheets of LVL (3m x 1.2m x45mm) which equates to a total 231 sheets
• Shear walls are made of four layers of 45mm LVL sheets, glue-laminated together to form a 180mm thick wall.
• Auditorium trusses contain approximately 3.5km of specially cut LVL
• Bracing and wall linings - approximately 1,000 sheets of plywood (overall centre)
• Roof and wall structure framing - approximately 3km of JNL J-frame (overall centre)

• Carter Holt Harvey utilised its laminated veneer lumber (LVL) product in the construction of its new Marsden Point manufacturing plant.
• Covering more than 2 ha, the building houses the assembly, pressing, finishing and despatch functions for LVL manufacture.
• The structural system involves rafters extending across the full 96 m width supported at four points, creating three 32 m spans.
• The outer columns are rigidly connected to the rafters to form portal frames while the inner columns act as simple props.
• The rafters are either 1,200 or 1,265 mm deep LVL I-sections spliced at six points.
• Outer columns are the same dimension but taper down to 800 mm at their base.
• Internal columns are box sections fabricated from 300 mm x 45 mm LVL.
• Composite plywood and LVL I-beam purlins span 11 m between rafters.
• In total, 620 m3 of LVL, 50 m3 of structural plywood and 15 m3 of sawn and dressed timber were used in the construction.
• This project demonstrates that large-scale industrial buildings can be built successfully with timber.