The elliptically shaped building with an asymmetrically placed circular inner core was designed for BMW Umhlanga in 2000 and the roof consisted of a concrete ring beam with a tensile tent-type structure attached to it. CMH Kempster Ford, the building owners decided to convert the building into their new flagship dealership that would satisfy Ford international’s CI. The original building had no thermal qualities and it was only projected by a 2mm membrane. Needless to say, the internal thermal comfort was not great and had to rely on mechanical cooling.
Steel was the obvious choice due to its flexibility, durability and aesthetic value. The steel members allowed for great long and shallow spans and also for it to be extended beyond the building façade for greater solar protection. Braced roof overhangs of 4,0m were achieved and bring with it an added aesthetic dynamic.
The roof super-structure radiated from the internal circular ring beam to the oval-shape external ring beam using a combination of gusseted rafters for the shorter spans to I beam/angle-iron type trusses for the longer sections.
Due to the geometry of the structure very careful consideration design innovation had to be given to the roof and side cladding. The roof structure was a series of overlapping circular rings and GRS recommended Ziptec due to its ability to be tapered around the circular roof-scape. Another reason for choosing Ziptec was due to its high wind-loading capabilities as the sheeting was laid on a six-degree pitch. Horizontally laid IBR sheeting was used on the vertical face of the elliptical building and each every sheet had to be specifically rolled to the correct radius to fit each segment of the façade. The balance of the building façade was a combination ColorPlus – S Profile sheeting fixed horizontally to large parts of the building as well as Hulabond HBS Aluminium System Panels attached to a curved steel sub-structure. The latter work was done by Façade Solutions and the Colorplus sheeting was prepared and supplied by GRS
Due to the complex and intricate nature of the design and installation of the project, it was imperative that all the stakeholders be involved from inception. Experience played a major role in the ultimate success of the project and the client employed two key professionals that were involved in the project when first constructed in 2000- 2001. The Engineer, Linda Ness from NJV Consulting Engineers and the Architect from Hans Coetzee Architect. Linda Ness nominated Impact Engineering for the work at hand and their input and manufacturing abilities proved to be a catalyst of the ultimate success of the project. Their only recommendation was that GRS be involved due to their ability to provide the correct sheeting and cladding products from a design and supply point of view. The timelines were manic due to the clients trading requirements but all parties got stuck in and delivered an awesome new building to CMH Kempster Ford. Hans Coetzee Architect provided the services of Project Manager and Principal Agent.
|Completion date of steelwork||30 MARCH 2018|
|Completion date of full project||30 MARCH 2018|
|Tons of structural steel used||UNKNOWN|
|Structural profiles used||I-BEAM / CHANNEL / COLD ROLLED ANGLES|
|SA content – if this is an export project||LOCAL SUPPLIER: IMPACT ENGINEERING|
|Completion date of cladding||26 JULY 2018|
|Cladding profile/ type used||ZIPTEK 420 0.8MM GR9017 HAZY GREY N/F
IBR 686 0.53MM AZ200 SLATE N/F
KLIPTITE 0.53MM AZ200 RAIN CLOUD N/F
|Cladding area/ coverage and tonnage||ZIPTEK 420 2326m² 7.310 TONS
IBR 686 359m² 2.900 TONS
KLIPTITE 159m² 830 KG
|PROJECT TEAM ROLE||COMPANY|
|Nominator||Global Roofing SA|
|Architect||Hans Coetzee Architect|
|Structural Engineer||NJV Consulting Engineers|
|Project Manager||Hans Coetzee Architect|
|Main Contractor||Impact Engineering|
|Steelwork Contractor||Impact Engineering|
|Steel Erector||Impact Engineering|