St John’s Gardens, Hackney

A comprehensive design and waterproofing solution was required to the basements of a new build residential development in Hackney

The Challenge

Situated next to the church of St John’s at Hackney, the new mixed- use residential development in East London consists of three structures including a four-storey building with basement, accommodating 58 mixed dwellings and community facilities. The development also provides a mix of residential types, including apartments and family houses with private gardens, a nursery and a semi- public urban square and communal garden.

Waterproofing Specialists Cast Contracting Ltd (CCL) were commissioned by JJ Rhatigan to design, supply & install a comprehensive structural waterproofing system to the basements of the new build residential development.

St John at Hackney

The solution

CCL’s design team recommended the installation of a Sika water management system, including sump pump systems, into the basements of each of the three residential blocks. An 8mm cavity drain membrane was installed to the concrete retaining walls and floor slab, above a 50mm water resistant extruded polystyrene insulation.

CCL included the installation of a periphery drainage channel including regular drainage ports to provide a fully maintainable system. Sikalastic 1k cementitious waterproof coating & protective drainage sheet was then applied to the blockwork upstands and concrete roof decks above the basement areas to prevent the ingress of water and complete the waterproofing works.

Client Testimonial

“Having been let down by another waterproofing contractor, JJ Rhatigan contacted Cast Contracting Ltd late into the project at Hackney Gardens to design and deliver a cavity drain waterproofing solution to very tight timescales. CCL were able to react to the last minute commission and their team of estimators, contracts management and operatives, were able to design and install the cavity drain solutions into each of the three basements. Their team could not have been more helpful and their professional approach to delivering the solution ensured that we were still able to meet the deadlines required for completing the project.”

James McHugh, Assistant Project Manager, JJ Rhatigan

Product Specified

  • Sika Anti Lime Coating
  • Sika Std Cavity Drain Membrane
  • Sika Std Cavity Drain Channel
  • Sikalastic 1k
  • Sikadrain 850

Design | Supply | Installation

Cast Contracting Ltd (CCL) is the UK’s leading specialist in Design and Installation of all Waterproofing, Tanking and Ground Gas Systems across the United Kingdom. CCL prides itself on offering the highest level of service throughout the Design, Planning, and Installation process.

Structural Waterproofing & Ground Gas Solutions

CCL’s in-house design team can offer a comprehensive proposal for all scenarios in line with BS:8102 and BS:8485.

CCL Guarantees

One of the most comprehensive Guarantees across the industry, taking full project ownership.


Cast Contracting Limited is one of the longest standing industry specialists. As it is now part of the CCL Group of Companies, Cast Contracting Ltd has the additional stability and support with over sixty employees across the Group.

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