Steps ahead

John Robertson Architects specifies Lazenby polished concrete for a feature stair at its Cannon Green office refurbishment

In association with
Credit: Seveer Media

Lazenby has been installed at a remodelled office building by John Robertson Architects (JRA) in the City of London. Named Cannon Green, the project incorporates a new entrance pavilion with a 4m-tall self-supporting feature amphitheatre staircase to create an inviting reception.

Self-supporting staircase in 12 weeks

The staircase, which has been specified on behalf of the client Ocubis, is 21m long, 7.5m wide at the top, was cast in-situ using Lazenby’s Pewter polished concrete and installed by eight craftsmen. Design by JRA and structural engineering by Civic Engineers, incorporating BIM modelling due of the intricacies of the reinforcement design. This self-supporting staircase is tied into the structure with a steel stringer to convert the loads and moments down through the steel columns.

Traditional formwork, RC and DDA studs

Lazenby installed traditional formwork to create the stepped soffit that leads up to the inverted amphitheatre steps. Lazenby then installed a false work system enabling the formworkers to create the radius former inverted amphitheatre undercarriage that is visible from the restaurant. Reinforcement was then added to the soffit and steps; carpenters added the formers and attached nearly 700 DDA studs to the formwork prior to the casting of concrete.

RC detail

A C32/40 concrete was supplied by London Concrete to form the Lazenby Polished Concrete staircase. The project used approximately 24m3 of concrete and 6 tonnes of steel reinforcement. Ground floor to the top landing features 24 shallow risers and three functional landings. The first 3m wide step widens to a 7.5m inverted amphitheatre style landing featuring single and double height steps.

  • Lazenby's finished polished concrete stair for John Robertson Architects.
    Lazenby's finished polished concrete stair for John Robertson Architects. Credit: Seveer Media
  • The inverted amphitheatre staircase at Cannon Green under construction.
    The inverted amphitheatre staircase at Cannon Green under construction. Credit: Seveer Media
  • The inverted amphitheatre staircase at Cannon Green under construction.
    The inverted amphitheatre staircase at Cannon Green under construction. Credit: Seveer Media
123

For more information and technical support visit: www.lazenby.co.uk

 

Contact:

info@lazenby.co.uk


 

Latest

Tintagel Castle Footbridge carries visitors off the mainland and into the past in a single, much easier, step. Creating it was anything but

Steel and slate pave way to King Arthur’s keep

Women’s contribution to architecture has long been overlooked. Two new publications bring recognition to many previously unknown names

Two new books start to redress the overlooking of female architects

Featherstone Young’s home for a pair of retired doctors in Rutland hugs the village boundary to avoid sprawl and preserve a meadow

The modern rural newcomer to Rutland that’s ‘a joy to live in’

Standardisation, DfMA, AI, IoT. Where do architects fit into technical innovations?

Are architects at risk of being sidelined?

Stone, timber, linoleum and an entry system feature among our latest ideas for interiors specifiers

Some of the latest ideas for interiors specifiers