In 2008 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.
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.
This project required the demolition of a 10 storey building and 2 basements within part retained sections of facade, and excavation for a 3rd level of basement. The existing basement was 7-8 metres deep and the new 3rd level required another 5 metres to be excavated.
The site is surrounded by narrow roads with poor access in a busy area of London. Supporting the facades and propping to support the existing basement walls whilst allowing for the new construction was challenging due to the additional level of basement to be constructed. There were 3 listed rooms within the building, one of which was due to be dismantled an re-built, and the other 2 retained in situ.
The existing 2 level basement walls were propped onto groups of raking piles. These along with the walings and props were installed during demolition thus allowing a fast programme with excavation proceeding immediately following demolition without delay for the installation of the temporary works.
Once the basement was formed 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.
Cemplas used various products to make the structure watertight. A joint and crack sealing strip was applied to any open joints, and at the ceiling/wall junctions a Koster mortar fillet was installed (Repair mortar plus) together with Koster NB1 Waterproof tanking slurry.
A Delta Cavity drainage membrane system (MS500 fixed to the walls & MS20 on the floors) was applied to the basement internally and a Delta Drainage Channel was installed to collect and manage water ingress.
Case Study Results
Located in the basement, the restored Atlantic restaurant spaces along with Dick’s Bar have become Brasserie Zedel, with Chez Cup being reborn as the successful Crazy Coqs cabaret venue, all being accessed from Sherwood Street. The fine Art Deco Titanic restaurant, also fully restored, has a new lease of life as a steak house, and is accessed from Brewer Street.
As well as the resturants the basement has a bicycle store room, WC, shower and changing room.