Site-laminated or made-up bearers

Bearers that have been constructed on site from shorter lengths of two thinner members are permitted when constructed in accordance with NZS 3604:2011 clause 2.4.4.7. For example, a bearer may be constructed from 2 x 90 x 45 mm lengths of timber instead of a 90 x 90 mm member. 

However, the laminations must be the same length as each other, and their ends must be coincident. This means that both members of the laminated bearer must be the same length as the solid bearer that it replaces. This stops the possibility that the bearer is only half its cross-section area where a pile crossing coincides with a staggered joint in the laminated members. In this situation, the laminated bearer could not carry the bending load like the solid case. 

NZS 3604:2011 does not permit the jointing of bearers over braced or anchor piles.

Reproduced from BRANZ Guideline January 2015

Published in building.