Design NexTimber CLT to AS 1720.1

NexTimber cross laminated timber is integrated in SPEC Toolbox for design to AS 1720.1. Twenty eight standard layups are available, from NX3/90 to NX9/360, covering 3, 5, 7 and 9 layer panels in 10 mm thickness steps from 90 to 360 mm. Panels are MGP10 graded radiata pine, manufactured at Tarpeena in South Australia and bonded with a heat resistant MUF adhesive. Panel properties are read from the integrated database rather than entered by hand.

NexTimber is the engineered wood products brand of Timberlink, manufacturing cross laminated timber at Tarpeena in South Australia. The integrated range carries a single board grade, MGP10 radiata pine, across 28 standard layups.

Thicknesses run from 90 mm to 360 mm in 10 mm increments across four layer counts: NX3/90 to NX3/120 in three layers, NX5/130 to NX5/200 in five, NX7/210 to NX7/280 in seven, and NX9/290 to NX9/360 in nine. Layer thicknesses within a layup are 20, 30 and 40 mm. Every layup applies to floor, wall and roof panels in both longitudinal and transverse orientation. Custom layups outside the standard range can be supplied on request, subject to lead time and order quantity.

Maximum panel width is 3.5 m, and maximum production length is 16 m, matched by 16 m domestic transport. Lamellas are not edge glued. The full range is bonded with a heat resistant MUF adhesive, with glue line integrity confirmed by the manufacturer. Surfaces are non visual (NVQ) or visual (VQ), and thickness tolerance is held at plus or minus 1 mm. Timber is PEFC certified, an environmental product declaration is available, and shop drawings and 3D models are supplied.

Load bearing walls, floors and roofs, across the full 90 to 360 mm thickness range in either orientation. Surfaces can be supplied non visual or visual. CNC machining and angled cuts are available for openings, service penetrations and non orthogonal geometry.

• A 10 mm thickness ladder across 28 standard layups, so panel depth can be tuned to whichever check governs rather than stepped in coarse increments.
• A thickness tolerance of plus or minus 1 mm held across the whole range, which tightens connection detailing and dimensional coordination on floor to floor build ups.
• Every layup offered in both longitudinal and transverse orientation, so panels spanning either direction come from one product range.
• Australian manufacture at Tarpeena, with 16 m production length matched by 16 m domestic road transport, so full length panels are deliverable without splicing to suit transport.
• Lamellas are not edge glued, a direct design input where in plane shear capacity and air tightness detailing are assessed.

NexTimber CLT panels appear across the SPEC Toolbox CLT modules: CLT floor, CLT wall, CLT shear wall, CLT diaphragm and CLT floor penetration. They also appear in the connection modules, in the screw connection module and the panel to panel connection details for spline, butt joint and half lap, together with the CLT floor to glulam beam, CLT floor to floor and CLT wall to wall connections.

Panel behaviour is taken from the integrated database with the exact characteristic values recorded for the MGP10 NexTimber grade. The same database values are used for design to the Australian and New Zealand standards. Fire design, vibration and other verifications not covered by the current standard can be checked against other relevant documentation.

Design follows AS 1720.1. The integrated database records the design code for every NexTimber layup as AUS, and carries the MGP10 NexTimber grade properties used in the calculations: E0 of 10 000 MPa with E05 of 7 000 MPa, a shear modulus G of 667 MPa and a planar shear modulus Gp of 67 MPa, f’b of 17 MPa, a rolling shear strength f’rs of 1.20 MPa, f’c of 18 MPa parallel and 10 MPa perpendicular to grain, f’t of 7.70 MPa, a density of 500 kg/m3, and joint group JD5. No European Technical Assessment and no ICC-ES evaluation report applies, because the panels are made and supplied for the Australian and New Zealand market. Charring rates for fire design are published in the NeXTimber Fire Performance Guide rather than carried in the integrated data.