Constructed originally between 1666 and 1679, the Castle of Good Hope in Cape Town is one of South Africa's oldest surviving buildings and it is still in use. It is the seat of the military in the city and houses the Castle Military Museum and the William Fehr Collection of Cape Town’s Iziko Museums. Military personnel, museum administrators and tourism support staff are at work within its four-metre wide walls.
However, inside the massive structure of the outer walls, there has been for many years a problem with the working environment. Despite the high thermal mass of the structure, the dark coloured roofing material has a high thermal conductivity and low insulating properties. This means the office space heats up through summer and becomes chilly in winter, once the inside walls have cooled to the ambient temperature.
The problem was initially addressed by adding resin-bonded fibre insulation faced with foil under cement tiles. This brought some relief to the building’s occupants but, some 20 years on, the glass fibre-based insulation had collapsed, material density went up and R-values went down.
Bambanani, planners of a scheduled roof maintenance programme at the castle, decided that both the insulation and the roof tiles had to be replaced. They approached various specialist companies and selected Eco-Insulation cellulose fibre insulation to be installed in the roof space and Mazista slate tiles to replace the degenerating tiles on the roof.
Richard Ellis, Eco-Insulation’s principal Cape Town agent, recommended that the existing collapsed insulating product be removed and that the Eco-Insulation be pumped in to the maximum possible depth of 110mm.
Founder of Eco-Insulation and managing director of the company, Cecil Homan, developed the unique, pneumatic pump delivery system to install the product into tight or inaccessible spaces. This was one of the factors that made Eco-Insulation a natural choice for this application. "The process is extremely simple and 100% effective," says Homan.
At the castle, tiles were removed from the crest of the roof so that the Eco-Insulation installers could remove the old insulation and create the space into which the new product could be pumped.
Homan says that this project once again demonstrates the versatility of Eco-Insulation as a retrofit product. "With the advent of SANS 10400-XA, insulation installed has to comply with specific R-values. When working within tight recesses such as the cavity between the sloping, vaulted ceiling and the roof at the castle, Eco-Insulation can simply be pumped into place to the required depth. The product distributes itself evenly into the space and mats together, providing a very effective and enduring barrier against the movement of heat."Why install expensive, energy-consuming air-conditioners, which require regular maintenance and servicing, when SABS-approved Eco-Insulation is a fraction of the cost? Eco-Insulation remains constant all year round and the product carries a lifetime guarantee. It does not deteriorate and promotes significant electricity savings. The cost of Eco-Insulation can be recovered through energy savings in plus or minus three years," says Homan.