R&D Contracting installs new roof for bottling plant
New roofing system will vastly improve in-plant lighting and ergonomics
The ABI bottling plant in Devland is a world-class manufacturing site, which has been producing cool drinks for the South African market for decades; however, as with any older facility, the plant’s roof was reaching the end of its natural lifespan.
The engineers who originally built it adopted an ‘origami style’ for the roof, which uses very specifically folded steel that is designed to be self-supporting. The origami style was not cost-effective, as although it is self-supporting, it uses large volumes of steel. Instead, the new design was based on the new roof on a previous project completed for ABI at its Wadeville Coca Cola canning plant.
We removed around six tons of steel from the roof every week, with it being replaced by a far lighter zinc aluminum composite – known as zinc alum – that is just 0.55mm thick. On average, the company is installing between 12 and 18 metres of the new roofing per day.
The galvanised support beams were specially designed for the project, and were certified by engineers, prior to implementation. We used Sisalation underneath the zinc alum roofing for the purposes of insulation, which is thinner than the previous insulation used, but thanks to a reflective coating on the outside, is just as effective at keeping the factory cool.
The Sisalation is a key innovation here, as it improves vastly on the old roof, which used sponge, fitted between double steel, for insulation purposes. Sponge works fine in a new roof, but as the roof ages, it becomes easier for this sponge to get wet, which adds extra weight to the roof.
The preparation included ensuring that the zinc alum roof sheets were rolled to the correct size, that the supporting beams were properly prepared and certified, and that everything was delivered to the site on schedule.
This high level of preparation was vital, as ABI needed the plant to remain fully functional during the re-roofing project. The nature of the plant is such that it would not be cost effective to ABI to shut it down for any extended period.
The intense preparation beforehand ensured that the project remained on track and, the new roof would be both safer and more ergonomically friendly and provide effective protection from the elements for several decades at least.
Johny Kruger, R&D's Site Manager at ABI Devland, points out that the new roof effectively improves the natural light coming into the plant. We used polycarbonate sheeting to allow sunlight into the building, with one in every five roofing sheets made of polycarbonate material. These diffuse the light and ensure that there are no bright pinpoints at certain times of the day which can be blinding and creates a safety hazard.
We used the colour Opal White, which offers the best diffusion of light and even though only 20% of the roof is composed of these sheets, it can increase the amount of available light entering the building from under 400 lux to upwards of 1300 lux. This does not only improve working conditions within the plant, but also reduces ABI’s electricity costs. We estimate that within a decade, the electricity savings should enable ABI to recoup the cost of the entire roofing project.
Due to safety laws around lighting inside a plant of this nature the minimum acceptable lux is around 500 lux. With the new roof, the plant achieves over 1 000 lux, even on cloudy days – and this is from natural light alone. Better lighting is also known to keep employees more alert and less likely to make errors, and generally improves the working conditions for all employees.
We will also be installing extractor fans in the roof to help remove fumes from the forklift exhausts, and improve the wellbeing of the employees.
The company has approximately 15 staff on site at any given time, which makes the issue of safety, health and environment (SHE) a critical one. SHE is very important to ABI and us, and is a vital component of a project of this nature. Regular medical check-ups are scheduled for all our employees focusing on hearing, eyesight and respiratory-related matters. These are then used as a baseline against which all subsequent tests can be measured and compared, in order to check for deviations from the norm.
Once on site we conduct regular ‘toolbox talks’ with employees. These meetings revolve around site-specific SHE issues and involve basic explanations of what to do and what not to do. We also conduct a site-specific risk assessment every week at the facility. Workers operating on the roof are fitted with redundant safety lines to ensure that risk is minimized.
For ABI staff to continue as usual while we replace the roofing, safety nets that can hold up to 400kg per square metre are placed underneath the working environment. These provide additional protection for our staff – should they accidentally slip and fall – and also added protection for employees in the factory from any accidents occurring that involve large items of equipment.