DATE OF PROJECT 2026
LOCATION Grey Lynn
When a heritage-style Grey Lynn property at 28a Mackelvie Street began showing signs of persistent dampness, Sansom was engaged to diagnose and resolve the issue. Our inspection revealed ongoing water ingress affecting the retaining walls and elevated moisture levels, With the original external waterproofing having reached the end of its service life, a sympathetic, long-term solution was required rather than a short-term patch.
Sansom delivered a maintainable internal Type C cavity drainage system based on the Newton waterproofing methodology. Working from a 50mm x 25mm rebate excavated at the base of the walls, our team fixed Newton cavity drain membrane to the wall surfaces, installed Newton Baseboard Channels. Rodding ports were incorporated to keep the system serviceable over its life.
Targeted repairs were also carried out in the server room, where a polymer-modified tanking slurry was applied to the prepared brickwork.
The result is a dry internal usable space. Newton waterproofing products are guaranteed against deterioration for 30 years, supported by CodeMark and BBA certification, and the works are covered by Sansom’s own workmanship guarantee, giving the client a durable, low-maintenance solution that will protect the basement for decades to come.
