Lumberworx LIB88


The Lumberworx I-Beam is engineered to create a strong but lightweight beam which is ideal for floor and roof systems. Its lightweight nature makes it easy handle on-site, while the strength of the LIB gives the builder and owner a quality floor they can rely on.


We stock the Lumberworx I-beams in the following sizes:

Thickness (mm) Widths (mm)
88 200, 240, 300, 360

These are available in lengths 3.0, 3.6, 4.2, 6.0, 7.2, 8.4 and 9.6m please check what’s available and lead times with our team.

Common Applications

Floor Joists, Rafters, Purlins, Wall Framing

Botanical Name Pinus Radiata
Standard Trade Names Pine
Origin Of Product Aotearoa (NZ)
Density 460 – 560 Kg/m3 @ 12% m.c.
Durability Class 4: Non-durable
Treatment H1.2
Finish Structural
LIB Size Joist Depth (mm) Flange Width (mm) Joist Weight (kg/m) øMx (kNm) øVx (kN) EIx (kNm²) GwAw N x 106
LIB200.88 200 88 4.8 12.53 17.2 518 2.6
LIB240.88 240 88 5.1 17.32 18.3 789 3.12
LIB300.88 300 88 5.6 21.44 18.8 1297 3.91
LIB360.88 360 88 6.1 26.94 16.8 1923 4.69


øMx Design Bending strength of section for bending about the x-axis.
øVx Design Shear strength of section for shear force in the y direction.
EIx Rigidity in bending about the x-x axis.
GwAw Shear rigidity for shear force in the y direction.
Ø Capacity reduction factor from NZS3603 Ø = 0.90


(Bending Deflection + Shear Deflection)
For a uniformly distributed load w, over a span L:
Y=k2(5wL4 / 384EIx + wL2 / 8GwAw)
For long duration loads k2 = 2  (Ref. NZS 3603:1993)

Cuts and Penetrations

The LIB uses timber treated in process, eliminating the need for any additional treatment being applied when the LIB web is cut. Please refer to page 8 of the LIB88s Design and Construction Guide for penetrations in floor joists.

Treatment +

The Lumberworx I-Beam (LIB) is treated to H1.2 hazard class. This is achieved by fabricating with all components treated to H1.2 by full penetration methods to the retention levels prescribed in NZS3640:2003 (including amendment 5).

Exposure of LIB to the weather for the period of construction is acceptable and will not result in structural damage. Exposure for longer periods may result in swelling and discolouration.

Channel Partners / Where to buy

Give the Lumberbank team a call, they are happy to point you in the right direction.

Call the lumberbank team

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