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Repairing a Deck at Gunwharf Quays, Portsmouth - Newton Waterproofing

Gunwharf Quays is a premium outlet retail destination located in Portsmouth with over 90 outlet stores, and 30 restaurants, bars and cafés. As part of the 2015 refurbishment project of the Quay, the main square, which serves as the central hub of both the retail and leisure facilities, was completely restored. Suspended above the underground car park, this was a significant project, which included removing the stone paving in the main square in order to uncover the existing deck waterproofing below.

Newton Waterproofing were asked to advise on the repair of the existing deck waterproofing, to waterproof new pipe penetrations, and to recommend and specify waterproofing for the retaining walls that would become a new landscape feature of the square, with grass banks on one side and seating areas on the other.


Newton Specialist Waterproofing Contractor Rubber Spray Solutions prepared the exposed surfaces and applied a polyurea membrane to repair the existing deck waterproofing. Newton's new, cold-applied, single-component seamless waterproofing membrane Newton 109-LM was then hand-applied around the pipe penetrations to prevent water leaking into the car park below, and spray-applied to the retaining walls and adjacent deck areas to prevent water seepage into the seating areas.

Newton 408 DeckDrain drainage membrane was applied to the newly waterproofed and repaired surfaces to protect the membranes and filter and reduce the flow of water onto the primary waterproofing layer.


The paving area, grassed areas and staircases to the mezzanine levels surrounding the square were soon reinstated and the square was returned to its normal use as an integral part of the Gunwharf Quays shopping and leisure experience.


"As a Newton Specialist Basement Contractor, we're always being kept up to date and supported with the latest product developments like 109-LM, and getting the right training for our contractors. The liquid rubber is something we’ve used before, and it's always really quick and easy to apply, regardless of how it's applied or what it's being used for. Using the drainage membrane alongside was good for this job too, as it meant the finishes could be put back in quickly, we got the square waterproofed, and Gunwharf Quays had the area back in use pretty quickly." – Simon Towers, Rubber Spray Solutions

For any further information about deck waterproofing, basement waterproofing or damp proofing please contact Newton Waterproofing Systems on 01732 360 095 or [email protected] or visit

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