Waterseal installed a full envelope waterproofing membrane at the Gnangara Underpass on Perth’s METRONET Morley–Ellenbrook line. The underpass was built using a cut-and-cover approach: the trench was excavated and then covered by a concrete roof. The original project update describes a structure over 100 metres long beneath Gnangara Road.
Why the envelope detail matters
Below-ground infrastructure can be exposed to moisture through the surrounding soil and at joints in the structure. An envelope system aims to provide a continuous barrier around the elements it protects. On a project of this scale, the membrane must be considered together with substrate preparation and the details where sections meet. The photographs below document Waterseal’s work at the underpass.
This post records a specific project rather than a universal design specification. The appropriate system for another structure depends on its construction, exposure and project requirements. Photographs show the scale and location of the works, but the design documents and site conditions would be needed to assess the technical specification. See Waterseal’s civil waterproofing services for related infrastructure work.
