Design Binderholz CLT to Eurocode 5

Binderholz (Binderholz Bausysteme GmbH, Fugen, Austria) manufactures BBS cross-laminated timber. It is recognized under ETA-06/0009, issued by DIBt. SPEC Toolbox designs the panels to Eurocode 5, using the characteristic values of the assessment.

The integration covers the Binderholz BBS cross-laminated timber, spruce C24 in every layer, glued crosswise at 90 degrees with a one-component polyurethane adhesive.

• 3 to 15 layers (commonly 3, 5 and 7-ply), element thickness 51 to 350 mm, board thickness 17 to 45 mm and width 80 to 250 mm.
• Systemformat panels up to 1.26 m wide and 5 m long, large-finger-jointed to 24 m; Grossformat and Grossformat DQ panels up to 3.5 m wide and 22 m long.
• Non-visual, industry-visual and domestic-visual surface qualities; thickness tolerance +/- 1 mm; PEFC chain of custody and a published Environmental Product Declaration.

At a glance, in the EU and ANZ scope the Binderholz BBS panels support:

• Load-bearing walls, floors and roofs.
• Service classes 1 and 2.
• Exposed (visual) or non-visual surfaces, with CNC machining and angled cuts.

• Declared board and panel values. The assessment declares a mean modulus of elasticity of 12 000 N/mm2 for the boards, with a panel rolling-shear strength of 1.0 N/mm2 and a rolling-shear modulus of 50 N/mm2 for the cross layers, used directly in panel design.
• Large formats and long panels. Grossformat panels reach 3.5 m wide and 22 m long, and Systemformat panels can be large-finger-jointed to 24 m, for long spans and full-storey walls with fewer joints.
• Tight thickness tolerance. Element thickness is held to +/- 1 mm, which helps connection detailing and dimensional coordination against the surrounding structure.
• Formaldehyde-free bond, documented sustainability. The one-component polyurethane glue line is formaldehyde-free (emission class E1), and the product carries PEFC chain of custody and an Environmental Product Declaration for embodied-carbon reporting.

The Binderholz BBS panels are available across the SPEC Toolbox CLT modules, worked to Eurocode 5:

• CLT floor, CLT wall, CLT shear wall, CLT diaphragm and CLT floor penetration.

and in the connection modules:

• the screw connection module and the panel-to-panel connection details (spline, butt joint and half-lap);
• 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 of ETA-06/0009, and the same values are used for design to the Australian and New Zealand standards. Fire design, vibration and other verifications not covered by the current Eurocode 5 can be checked against the new Eurocode 5 and other relevant documentation.

Design follows Eurocode 5 (EN 1995-1-1). The panels are assessed under ETA-06/0009, which supplies the characteristic values used in design, including the board modulus of elasticity (12 000 N/mm2) and the rolling-shear strength and modulus of the cross layers. Characteristic values are reduced to design values with the Eurocode load-duration and service factor and the material partial factor; the bending strength is reduced for large-finger-jointed panels and the in-plane tensile strength is reduced, per the assessment. The assessment is for service classes 1 and 2; airborne and impact sound insulation, and resistance to fire, are not assessed in the ETA.