There are many scaffold structures like marine scaffolds and boiler scaffolds that need to be designed due to the loadings and calculations needed for each scenario. Dead shores and bridges are a structure that supports a dead load i.e for the support of concrete floors or for supporting heavy items with the load imposed directly above the designed scaffold structure. There are other shores including flying shores that are a designed to impose no load to the floor area and this option is used for supporting internal walls normally erected if the lower floor levels are to be demolished. Another option is the raking shore used to support external walls if there is subsidence or to support a building whilst demolition work is in progress. Designs also include cantilevered scaffolds where the structure is erected and then bridged out off the existing scaffold at high level to access roofs and large soffit areas.
Truss out scaffolds are used when there is no access at ground level. This type of structure is erected off an existing floor usually at high level with scaffolding erected using beams to create a working platform outside the building without erecting the scaffolding from the floor. This type of design is used at high level to save time and materials. Access birdcages can be designed to access to internal areas at high level and erected in stages to cover the works. Buttressed free standing scaffolds are erected when there is no building to tie to ie for the renewal of power line crossings when the framework is free standing in a field or by the side of a carriageway. Temporary roofs and temporary buildings need designing due to the span needed to cover the building and to take into consideration wind loadings imposed on the scaffolding structure.
All heavy duty support scaffolds including spectator terraces and seating stands need designing to make sure they are capable of holding the loadings imposed and this includes loading bays founded on the ground. Mobile and static towers outside base/height limitations including free standing scaffolds outside base/height limitations need to be designed to make sure they are safe to work on. These towers if they exceed their smallest base dimension will require guys or ground anchors to support them. Pedestrian footbridges and walkways need scaffold design to provide temporary ramps and elevated roadways to span over a carriageway for access. With advertising hoardings/banners and sign board supports the wind loadings need to be taken into consideration making scaffold design a necessity.
Slung and suspended scaffolds including steeple scaffolds are erected when there is not access at ground level. This type of access is hung from the building erected at high level using scaffold tubes and fittings or wire bonds.
Protection fans are installed to scaffolds where the risk of falling debris in apparent. Incorporated with the protection fans nets can be installed to stop any falling debris from the scaffolding. System scaffolds outside users guide parameters are system scaffolds erected above 5m and need scaffolding design and drawings for erection. System staircases and fire escapes can be incorporated with lifting gantries and towers for access to remedial works.
Access scaffolds with more than the 2 working lifts allowed with TG20 `basic scaffolds` need to be erected by an advanced scaffolder requiring scaffold design and calculations .Offshore scaffolds outside offshore contractors association (OCA) handbook including masts, lighting towers and transmission towers are specialist types off scaffolding requiring scaffolding design due to the exposed locations this type of scaffolding is erected in.
Any scaffold with high loadings in high risk areas that is erected for long term duration will require scaffold design as per the construction (design and management) regulations 2007.
Any scaffolding structure subject to a scaffold design will need qualified engineers to provide drawings and calculations that will need to be approved prior to starting works.
Find below an example PDF of scaffold designs.....