Eskom’s Pumped Storage Scheme, which is situated in the Drakensberg, is one of the largest power stations of its calibre in the world. This station generates 1 000 MW of electricity for the national grid during peak hours.
Very little of the plant is visible to the naked eye as most of its installations are underground. For curious visitors to the area, Eskom’s Drakensberg Visitors Centre, which is situated nearby the plant, offers presentations, brochures, an exhibition and guided tours showcasing this extremely interesting example of South Africa’s technology and diversity of engineering disciplines.
When renovations to the roof of the visitors centre were deemed necessary, Eskom awarded the contract to specialist contractor John Cairns, who confidently specified Sika’s high-performance SikaRoof MTC 12 system for the job. The system boasts European technical approval. It was the ideal choice for the project due to its ease of application, especially around the ducting and detailing on the roof, and its effective long-term weatherproofing protection.
Preparations to the 300m2 roof involved removal of the original torch-on system and, since it was a timber roof, the application of a carrier membrane prior to the application of Sika’s Moisture Triggered Chemistry (MTC) system. The roof was coated with Sika Coldstick, a two-component, solvent-free, polyurethane adhesive ideal for bonding Sikalastic Carrier. This adhesive is a highly effective carrier membrane incorporating dimensionally stable glass reinforcement and a modified elastomer coating.
The SikaRoof MTC 12 system consists of a base coat of Sikalastic-601 BC reinforced with rolls of Sika Reemat, a glass-fibre mat, and then sealed with UV stable Sikalastic-621 TC (top coat). These Sikalastic products are cold-applied, seamless, and highly elastic polyurethane coatings. It provides easy application, especially for roofs displaying complex detail areas where accessibility is limited. The products are fast-curing with the ability to rapidly become resistant to rain damage. Both coats were applied at a total consumption of 1,1kg/m2.
The temperature range for application of these products is 2oC to 35oC, and as this project commenced in June 2011, temperatures on site in the northern Drakensburg obviously reached very low levels. The contractor ensured that the weather conditions were conducive to the application of the products.
With its proven technology and track record, Sika’s world-class SikaRoof MTC 12 system guarantees a durable waterproofing solution ensuring that the Drakensberg Visitors Centre will be welcoming members of the public for many years to come.