Curved Concrete Staircase Manufacturing, Transport & Installation
Manufacturing Considerations
During the manufacturing process, Kallisto storey height flights are manufactured upside down on industry-leading adjustable palletised moulds. These moulds are extremely versatile which in turn, does not limit our clients to set configurations or profiles giving you the freedom to tailor a bespoke staircase to your exact development specifications. However, there are a few constraints that must be noted:
Plan Angle - due to the limitations within our factory, the maximum plan angle for any one flight is 270°
Riser Range/Flight Width - For stair flights with a riser range of 165 – 205mm, we are limited to a maximum flight width of 1250mm. For stair flights with a riser range of 185 – 225mm, the maximum flight width is 1600mm.
Soffits - as the flights are made “upside down”, this will have a trowelled finish and will have cast in lifting anchors to enable the units to be lifted off the mould. These soffit lifting points may also be used to secure the precast unit onto the delivery vehicle. The soffit will require a plaster finish by others after installation.
Treads, Risers and Strings - these will have an ex-mould finish but cast in lifting anchors are required to turn the units over after demoulding, and to lift the precast concrete units on and off the delivery vehicle.
Transportation
As a division of Milbank Concrete Products, we have access to a plethora of delivery vehicles from within an industry-leading logistics network. Our specialist precast concrete stair units are carefully loaded at our factory headquarters in Essex and delivered directly to site in preparation for installation all over the United Kingdom.
In some cases, if the width of the stair unit on the delivery exceeds 2.9m, the load is categorised as “abnormal” and will be subject to certain restrictions. We are more than happy to assist with support vehicles/abnormal delivery requirements if necessary. The maximum height of a load is 4.5m, so in some instances it may be necessary to use a low loader rather than a standard flatbed vehicle.
Installation
We are well equipped to provide a safe and efficient installation service should it be required. We have a collection of professional fixing gangs with years of experience in installing complex and challenging precast units and work closely with Mobile Crane Hire experts Cadman Cranes to provide safe and professional lifting services.
Precast stair flights are heavy, typically ranging from 2 to 12 tonnes in weight, so a mobile crane will be required to off-load the delivery vehicles and hoist the precast concrete units directly into position. It is important to note at this stage that we can only supply and install our precast units if access is available via the roof. Due to the weight and size of our precast flights, installation is not possible in renovation developments where the roof is still in place and our flights unfortunately cannot be maneuvered on the ground using trolleys.
The assumed size and operating radii of the crane will be stated in the quotation. For example, when using a 35-tonne mobile crane, the area occupied by the crane when fully rigged is typically 12m x 8m. The actual sizes are to be confirmed after a site inspection and will be clearly stated within the job specific lift plan and safe working method statement.