A grand design at Warehome Mews, East London

18 May 2018


Basement type: New build Building type: Residential
Type of waterproofing: Type A & C Member: Newton Waterproofing Systems 
Other: Constrained site  

The Project

Fed up of renting in London, Joe and Lina decided to build their own on a tiny 38m² plot of land in East London. With a budget of just under £200k they set about delivering Joe’s innovative concept for a six half-floor house with floating concrete slab, designed to maximise the space into a 83m² home, all whilst being filmed by Channel 4’s Grand Designs. However, the project soon became the Problem Project.

Within weeks of the project beginning in October 2015, a basement excavation had been attempted (by a non-approved contractor) contrary to the structural engineer’s instructions, leaving unsupported banks of earth falling in beneath the street. This first attempt, described as “spectacularly shambolic” by Kevin McCloud, more than doubled Joe and Lina’s budget for the excavation from £48k to £100k, and caused months of delays in order to get the project back on track.

The Solution

Joe worked together with Newton to determine how best to salvage the project and his home. The solution was to use a specialist contractor to actively communicate, collaborate and listen to him as both the engineer and client. MJ Rooney Construction came on board as contractors in November 2015, and following discussions to determine exactly what was required, modelled the entire project in 4D to ensure that all potential difficulties were solved before work began.

With the right lines of communication in place, work recommenced in late January 2016, with the first challenge being to make safe a 3.5 metre high bank of unsupported earth with sheet piles, before creating a new and waterproof structural shell of reinforced concrete.

Innovative Engineering

With the shell of the structure in place, Newton and MJ Rooney’s next challenge was a much more welcome one, as they created a bespoke waterproofing solution to accommodate Joe’s ingenious design for a suspended reinforced slab that acted as both a floor and a prop force against the lateral pressure from the basement walls. 

This entire slab rested on brackets designed by Joe and his structural engineer, insulating it from the external walls by ensuring minimal contact, and only making contact through insulated blocks with enough compressive strength to take the vertical loading. The design also created a cavity around the slab that can be fully insulated, allowing the slab to be used as a thermal mass inside the building without having to insulate the entire external envelope.

Working closely with Joe, a solution was devised that enabled the continuity of the waterproofing behind the brackets without compromising the structural design.

Completing the Grand Design

With a pristine below ground and waterproof concrete structure in place, complete with ‘floating’ slab, MJ Rooney and Newton handed the site over to the next stage in June 2016.

Despite the overall project cost coming in at £250K for Joe and Lina, to overcome such challenges and revive their dream home from a collapsing hole in the ground is a testament to the power of collaboration and teamwork between supplier, contractor, engineer and client.

The Products

  • 104 - Crystalline waterproofing applied to the surface of concrete to protect against the movement of water through capillaries and hairline cracks.
  • 106 FLEXPROOF - Highly flexible and extremely advanced single-component membrane that can handle severe building movement and deformations.
  • SYSTEM 500 - The professionals’ waterproofing system of choice, this internal and fully maintainable system is ideal for new build or refurbished basements, utilising floor and wall membranes, fixing plugs, sealing tapes, drainage channels, insulation boards, and sump and pump chambers.
  • 906 LIME INHIBITOR - Applied to concrete surfaces prior to System 500 installation, 906 prevents the leaching of ‘free lime’ from the concrete
  • CP250 PUMPS - Used with the Titan-Pro White, these high quality clean water pumps are ideally suited for removing groundwater from basements and cellars.

See Newton Waterproofing's Company Profile