An important performance characteristic of Zincal® and Colorplus® in alloy coating thickness AZ200 is its ability to withstand corrosion and degradation under severe coastal conditions.

This case study shows how Colorplus® AZ200 was correctly specified and installed as Saflok 700 roof sheets and cladding at the recently announced Materials Recycling Facility (MRF), which is located within of 700m the pounding surf of False Bay at Muizenberg, Cape Town.The zone is also subject to heavy particulate loading from the prevailing south-easterly, sometimes gale-force winds blowing direct off the sea.

Our case study highlights the following benefits

1. Colorplus®, along with its uncoated substrate, Zincal® is manufactured in KZN by Safal Steel, a licenced user of the tested and proven  55% Aluminium, 43.5% Zinc and 1.5% Silicon coated steel technology from BIEC International Inc. Safal Steel is the first and only licensed producer of this patented coating alloy in Southern Africa, which is used to manufacture the highest quality metallic and pre-painted coated steel used in roofing, cladding, and many other structural applications.
2. The alloy coating on Zincal® and Colorplus®  protects the roof sheet: The aluminium part of the coating provides a tough physical barrier, while the zinc component  provides sacrificial protection, also protecting the steel at the cut edges. Hence, the service life of the steel core is up to four times longer than that of conventional galvanized. An additional major sustainability advantage of Zincal®  or Colorplus® is its lightweight nature when compared with galvanised steel. This is in line with dematerialisation, lower transport costs, longer life in service all supporting sustainable outcomes.
3. The factory-painted coating on Colorplus®, contains innovative pigments which have been carefully selected to keep both its specified colour and retain a fresh appearance for many years. The technology used for this coating system also limits chalking. Particle resistance is an important factor with the growing increase in windborne contaminants and dust. Advances in our paint technology means that our modified polyesters resist dirt, ensuring your building stays cleaner for longer.
4. As one of the most effectively recycled materials on earth, it is highly appropriate that coated steel of these superior characteristics should have been specified for a building that will be used for the separation and recover of re-usable and recyclable materials from household and commercial waste – as per the City of Cape Town’s Solid Waste Department.
5. The specified Colorplus® AZ200 roofing and cladding roofing profile on this job was Saflok 700, an interlocking roof and cladding sheeting fixed to internal purlins using the suppliers approved clips.These are concealed from  the elements and fastened to the roof purlins In line with the manufacturer’s recommendations. In a highly windswept coastal park area such as within the City of Cape Town landfill facility near Muizenberg beach,  this is the sensible way to go in the face of such prevailing high wind.

The City of Cape Town confirmed that the MRF facility is expected to start operating around mid-November 2024, but could be completed ahead of schedule.

The project was initiated by the City of Cape Town’s Urban Waste Management Directorate and will separate and handle all material waste. It is designed to receive co-mingled clean and dry recyclables, and separate the materials so that they can be sold and used in manufacturing of new products. The MRF will provide capacity for sorting 65 tons of recycled material per day.

This will include not only builders’ rubble, but plastic waste, among others: “Increasing plastic pollution is a global issue. It is affecting even very remote environments. Currently private collection of recycling is prohibitively expensive for many citizens, and use of drop-offs is sometimes inconvenient, so I am very excited for completion of this facility. This will allow thousands more families to start cleaning and separating recyclables from their general waste for collection by the City” said Alderman Grant Twigg the Mayoral Committee Member for Urban Waste Management. .

According to the City of Cape Town’s engineers:  “The MRF building is made predominately of structural steel but with the first 3m height of the building being made up of reinforced concrete columns and walls. The assists with extra protection from potential damage caused by operations as they move through the facility.

“The roof sheeting and cladding is a zinc-alum formed steel sheet.  The facility is within 500m of False Bay, and directly in the path of the notorious South Easter winds that batter Cape Town during the summer months, which means the Coastal Park MRF can be considered to be in a severe corrosion risk zone. An extremely severe risk zone would suffer the wind and be directly in the splash zone. Hence, consideration for the structural elements was particularly focused on galvanising of the structural steel, as well as adding duplex painting systems to provide long-term corrosion resistance. Zinc and aluminium-coated steel roof sheeting also provides some additional protection.

“It has become even more evident during the construction period that the site is prone to “sandblasting” from the nearby sand dunes that often block nearby Baden Powell Drive after a sustained period of wind. This sand is lifted into the air and batters the southern-facing sides of the building and infrastructure. The driving wind mixed with sand has the same effect over time as sandblasting of steel, and strips the infrastructure of its protective coatings overtime. Ongoing maintenance and making provision for the replacement and re-application of protective systems is critical to ensure longevity of the facility”.

Project engineer, Tim Davidson of JG Afrika Engineering confirms: “We used AZ200 as we are approximately 500m from the sea and the south east wind over False Bay is notoriously strong over Cape Town’s summer months. The environment is therefore highly corrosive. All in all approximately 20 000m2 of Saflok 700 was laid,Professional team: consisting of Safal Steel Colorplus®.

“The roof itself is supported by 50m spanning structural steel trusses spaced at 6m on combined steel lattice and concrete columns. The columns in turn, are supported on piled foundations driven 6 – 8 metres through the landfill waste on the site to the sand base. Under the roofing is 2 hr fire rated NC 502 insulation. All the structural steel is galvanized and coated with epoxy paint due to the high corrosivity of the building’s location.

“The roof itself has prominent elevated box structures in a light colour roof material, running parallel with the roof trusses, to provide space allocated for smoke extraction units and smoke curtains in the event of fire. These are needed as the facility can contain large volumes of highly flammable waste”, Davidson advises.

Area of roof and cladding: 20 000m2

Safal Steel: Colorplus® AZ200 in TCT 0.53 and colour Raincloud – roofing and cladding.

Role formed by: Safintra in Saflok700

Client: City of Cape Town

Principal agent: WSP and JG Afrika Engineers (initial stages)

Civil engineers: JG Afrika Engineers

Architects: Jakupa

Landscape architect: Megan Anderson

Quantity surveyors: Talani and BE Clinic

Mechanical, Electrical and Electronic Engineers: CA du Toit

Contractor: Power Construction

Roofing sub-contractor: Chartwell

Roofing and cladding    role former: Safintra

Roofing material: Safal Steel

Site photography: City of Cape Town and JG Afrika

Location satellite image: