Nissan South Africa

R&D Contracting provide new roofing cover for can manufacturing giant

Implementing new, 54 000m² roof requires a pioneering approach.

Nissan South Africa’s assembly plant in Rosslyn, Pretoria, produced over 50 000 vehicles during 2014. This massive plant, which assembles the NP200 half ton bakkie and NP300 Hardbody one-ton pick-up, along with various other model Ds and derivatives, plays a key role in the company’s strategy to secure a significant share of the new vehicle market in Africa and South Africa.

The plant itself has been operating since the 1960s, and therefore certain parts of the facility were reaching their end-of-life, especially the plant’s roof. In particular, water leaks were becoming more and more apparent, and it was decided to replace the structure.

The initial planning stage of the project began in October 2014, which included order planning, tender documents, equipment orders and initial site planning. This was followed by site establishment, moving all the necessary equipment on site and ensuring that all employees involved in the project were trained to requirements. Once all of this was done could the actual site preparation begin. This involved the cleaning of gutters and surfaces, prior to beginning the actual installation. In projects of this size, it is inevitable that there is a long preamble before the actual work gets underway.

The total scope of the project covered some 54 000m², and once completed will come with a 25-year life expectancy. In addition, we also installed the downpipes and launders that transport water from the roof gutters away from the building. These could only be installed on weekends only, and were only allowed to work when the plant was shut down.

We were informed that the original roof was installed in1967, making it very old and in desperate need of refurbishment. With expensive, specialised equipment within the plant, water leaking through the roof and its potential to cause damage was a problem, and in order to overcome this, we chose to implement a specialised system that is designed to negate the possibility of water leakage, particularly around the screws which are used to hold the roof in place.

By fitting a new roof using the AshGrid spacer system from Ash and Lacy, we were able to avoid such challenges, as this system uses a clip-lock operation that allows the roof sheets to simply be clipped into the spacers already placed on top of the original roof. Since the spacer brackets are fitted to the original roof with 25mm tech screws through the existing roof purlins, and the new roof sheeting is simply clipped onto these brackets, the existing roof is completely concealed allowing no leakage through the holes made for the tack screws.

This system is also designed to withstand winds of up to 280 km/h. This is more than 100 km/h faster than most other roof sheeting systems.

When it came to this project, thinking on our toes and bringing innovative ideas to the table was a must

  • To transport the heavy roof sheets and spacer system to the roof, we made use of a lifting system imported from Germany that can carry up to 250kg, and lifts the heavy roof sheets up the side of the building and on to the roof. This was not the only innovation we brought to this project.
  • The sheer size of the roof meant that moving the heavy roof sheets from one end of the roof to the other – a distance of 300m – would be extremely time consuming and labour intensive. Therefore, we invented a solution that would solve this challenge, in the form of a trolley system that we installed temporarily across the existing roof.
  • It was discovered that the existing air vents on the roof had a tendency to act as water traps during a downpour, creating pools of water that had the potential to create additional leakage problems. To combat this we designed what we call ‘backflashing’, which was created on the fly from offcuts of roof sheeting. By placing it at a 90 degree angle to the rest of the roof, we were able to create conduits that channel the water flowing down behind the vents off to the sides, where it can easily run off into the existing gutters.

 

Ultimately, a project of this nature is vast and intensive, and requires plenty of innovation. In other words, it is an ideal project for us, as it enables us to use our technical skills in a way that will provide Nissan SA with a new roof that will withstand the elements for decades to come. Perhaps the most enjoyable aspect of this particular project is the manner in which it has driven us to find new ways of operating and allowed us to demonstrate our ability to be truly innovative.