Quadrant 2, Regents St

Quadrant 2, Regents St

Client: Sir Robert McAlpine
Role: Specialist Sub-contractor


  • Waterproofing
  • Concrete Repairs


  • £500m redevelopment, Regent Street, London’s West End
  • Waterproofing and concrete repairs to basement and soffits beneath retail areas
  • Delta Cavity membrane drainage system applied
  • Delta Drainage Channel installed
  • SikaDur Combiflex applied
  • Koster mortar fillet installed
  • Concrete repairs undertaken

The Crown Estate undertook a £500m redevelopment on Regent Street in London’s West End restoring the Café Royal as a six star Hotel, and the Regent Palace Hotel block to provide residential, retail, office spaced and a cultural quarter. The historic art-deco Atlantic Bar and Grill and Titanic Restaurant will be preserved, together with refurbishment to the Retail Arcade blocks known collectively as the Quadrant.

Quadrant 2, Regents St

Appointed as the main contractor, Sir Robert McAlpine were the tasked with undertaking one of the most ambitious projects, seen in the West End.

Working as a specialist contractor, Cemplas Waterproofing and Concrete Repairs Ltd were awarded the multi-disciplined waterproofing and concrete repairs to Quadrant 2 retail building.

Cemplas put forward varied proposal to carry out Waterproofing and Concrete repairs to the basement and soffits beneath retail areas in Regent and Air Street. Waterproofing was also required to the plant rooms, store room, stair lobby, and corridor, together with specialist screeding work.

Using all their expertise from over 40 years of complex refurbishments, Cemplas proposals included using a varied range of specialist products which their operatives are trained and approved by the manufacturers to apply.

Delta Cavity membrane drainage system was applied to the vertical surface within the Arcade basement, and a Delta Drainage Channel was installed. SikaDur Combiflex was applied to any open joints, and at the ceiling/wall junctions a Koster mortar fillet was installed together with Koster NB1 Waterproof tanking slurry.

On the ground and first floor slab, a specialist screed wad laid using Ronacrete Uniscreed Standard cement replacement to reduce the level of retained moisture within the screed and allow a quick curing period. Areas that required concrete repair were undertaken using a Gunite technique pneumatically spraying the repair mortar through a hose and projecting onto the surfaces

Cemplas are proud to have played a part in this major redevelopment of this area which will secure and improve its long-term viability for future generations of visitors to our capital city.

Quadrant 2, Regents St