The project entailed the construction of a roof structure, The brief required the structure to be constructed from non-combustible material and suitable to meet the hospital’s requirements, supporting PV panels, and able to bear the weight required for theatre equipment
The project was envisaged in steel from the start, due to the success of previous projects of a similar nature. MiTek ultra-span, was opted the best product for the project, because of its ability to clear span up to 40m.
A brief description of the structural framing and use of LSF
The structural framing consisted of cold rolled, specially designed, sections in various profiles and thickness, one-sided assembly and cut to length. The project team used inverted shape trusses of Mitek Ultra-Span components. With truss spans ranging between 14m and 20m clear spans.
The roof trusses were manufactured in Rooftek’s factory and transported to site. Roof sections of approximately 150m² could be assembled simultaneously and then lifted in position.
What is special/ unusual/ innovative/ aesthetic about the steelwork/cladding in this project?
The roof structure was detail to be supported in-between the concrete ring beams on brackets. In some places the trusses were supported on the RC beam (shafts etc). This created challenges during the design, costing and erection phases.
Designer Jaco van Wyk from MiTek Engineering Cape Town created a cost-effective framing solution. The erecting of the roof structure was simplified by assembling portions on the concrete slab and lifting the required sections into place. This enabled optimization of connections of the trusses, enabled services to be connected and reduced torsional moments on the concrete ring beams. The inverted shape roof truss provided a structurally sound roof design to accommodate services and Solar PV panels to the one elevation of the roof structures
How did the project team work together (e.g. contractor involved early, challenges/ ease of communication etc.)
The project was driven by Kalahari (Rooftek) from the tender phase. All design aspects and complexity of the roof structure was discussed with MiTek, the architect, engineer and project manager on site prior to the final designs. This close collaboration eliminated many potential problems prior to manufacturing and erecting of the roof structure.
Key areas that were managed with excellence include:
- The box-gutter detail required
- Fitting in with the previous buildings.
- The additional steel sprockets to match the existing.
|LSFB / LIGHT STEEL FRAME BUILDING WORK|
|Completion date of LSFB work||2019|
|Tons of LSF used||27478,85 kg|
|Span of trusses and Kg/m2 (ifapplicable)||Span 15920m|
Designed & Inspection (MiTek)
|Roofing and Cladding||Global Roofing Solutions|