Accreditations
Cheshire Scaffolds Ltd
Haigh Ave,
Whitehill Industrial Estate,
Stockport,
Cheshire,
SK4 1NU
Leftbank, Spinningfields, Manchester
Cheshire Scaffolds Limited (CSL) were appointed to design and deliver a comprehensive scaffolding solution to support a major external refurbishment project on an occupied building within Manchester city centre. The works involve the installation of new fire barriers and the full removal and replacement of the existing façade. The project required carefully coordinated access arrangements to maintain resident safety and minimise disruption throughout the project.
These complexities included:-
- Providing a cantilevered scaffold (40m high) over the River Irwell (Case Area 1).
- Providing further bridged & cantilevered scaffold (40m high) above busy pedestrian & vehicle
routes (Case Area 2). - Providing a bridged & cantilevered scaffold (42m high) over a low level non load bearing roof,
including supporting a goods hoist off the scaffold bridge (Case Area 3).
Case Study Area 1
The task was for CSL to design and build a cantilever scaffold carrying 20 x boarded lifts of scaffold which was further complicated by a projected wide balcony due to building construction. In addition the rear tail uplift from the weight of the cantilevered scaffold could not be transferred into the underside of the building floor slab.
After initial design assessments & guidance from the designated permanent structures design engineer team, it was decided to transfer & support this cantilevered load into the rear of the local concrete columns. This resulted in distributing a combined uplift load of 28.09kN along cantilevered 750mm Alloy X Beams via 4 No. ADI SCB16 4 Hole Bolt Shear Brackets.
All works were to exacting safety standards and compliant with Working at Height
Case Study Area 2
The task was for CSL to design and build a combined bridge, cantilevered & pedestrian protection gantry scaffold, carrying 17 x boarded lift levels of scaffold. Further complicated by being erected above both live traffic on a major network route into the city centre and above a live pedestrian route.
Project was achieved by utilising 750mm Alloy X Beams in both primary support (for the pedestrian gantry) and secondary support for bridging over ground-based obstacles. Additional vertical 300mm ladder beams were used to support the outer frame of the gantry protection due to limited width of the existing pedestrian footpath.
Case Study Area 3
The task was for CSL to design and build a 20 x boarded lift scaffold over a non-load bearing roof. This was further complicated by the structural nature of the building only providing 2 limited area’s that the scaffold could be support from along its length, plus the change of building fabric throughout its full area. To further complicate the design, this scaffold above the roof would also be required to support an 18m high Goods Hoist platform.
After initial design assessments & guidance from the designated permanent structures design engineer team, the challenge was to erect a support scaffold framework running parallel and 9m from the face of the building. Allowing the construction of multiple heavy duty 1500mm Alloy X Beams, to act as primary spine beams to provide a centralised support position for the main supporting secondary beams. This is due to the large span between the building inner return and a ground-based support scaffold. Similar to Case Area 1, these heavy-duty beams were fixed to the one & only concrete beam column along this elevation supported via several ADI SCB16 4 Hole Bolt Shear Brackets. This spanned between the building column and the newly formed outer support scaffold, immediately above the low roof.
This provided the required support framework for the Secondary 750mm Alloy X Beams running parallel with the building line, allowing the birdcage infill above the low roof to act as a loading area & access point for a low-level hoist from the ground. This same birdcage framework was also required to withstand and carry the load from an 18m high Goods Hoist, inclusive of the dynamic impact load it creates during its operation. The scaffold immediately adjacent to the high-level building also required to provide erected and provide access to its full height.
The initial calculations for the overall load of the entire scaffold SW & LL erected over the low roof and supported by the central column alone, was over 200kN. Added to this, the load from the Goods Hoist this created its own challenges, which were further enhanced due to the challenging factors the building structure provided. The initial main challenge being only 2 support locations along its length that were capable of supporting any load in shear.
The agreed solution was to repeatedly transfer the supporting loads up the building line, thus allowing over 40 supporting shear tie locations spread vertically along the column and slab, to as not to risk overloading of the potential minimal support pinch points. On completion of the initial design, the CAT3 check from the permanent structural engineer was successful with the provision of Design Engineer Inspections to be conducted as the scaffold build works progressed, to ensure all supportive ties installed correctly and no signs of physical decay or settlement to the building structure.
