Highways Waterproofing on SH20A


A major highways improvement project was undertaken on SH20A in 2017. The project was undertaken by MHX Kirkbride Alliance and involved the construction of an underpass underneath Kirkbride Road. The deep excavation required construction of concrete diaphragm walls, retaining walls, sumps and carriageway. This excavation was in wet ground with a high water table which posed significant waterproofing challenges.

Maxbuild installed Sikadur Combiflex SG tapes to the diaphragm walls. Construction joints in the diaphragm walls were sealed before any leakage could occur using leak sealing resin injections.

The largest section of the works involved waterproofing of voids, sumps and transition slabs with SikaProof A and SikaProof P.

Maxbuild had significant challenges in completing this work. Firstly, the works were on the project’s critical path so no delays could be accepted. Secondly, some of the installation  required sequencing with main contractor’s construction team such that a high level of supervision and project management was required.


Kirkbride Road, Auckland



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