Concrete tiles are increasingly becoming the roof covering material of choice for a variety of practical reasons, says Bryan Perrie, MD of The Concrete Institute.
Perrie says the development of sophisticated computer modelling systems has elevated roof design and construction far beyond the most basic functional purpose of shelter and into the realm of architectural sculptural showpieces. “In line with these trends, advances in concrete technology and waterproofing technology make it possible to transform fantastic concepts into impressive reality,” he states.
“Due to the durable nature of a concrete structure, a building envelope can be designed to accommodate a variety of functions over its lifespan. Examples of whole buildings being ‘recycled’ can be seen in the inner cities of Johannesburg, Pretoria and Cape Town where previously vacant office blocks are now being converted into affordable residential units close to job opportunities.
“Designed accordingly at the inception phase, flat concrete roofs can allow for additional storeys to be added later as the need arises, or funds become available, for increased densification – further optimising the use of well-located land and existing services.
“As the demand for available land in the city centre increases, there is increased pressure to develop current open green spaces. With city centre space at a premium, a flat concrete roof presents an innovative opportunity to off-set the carbon footprint of a building by re-introducing the potentially lost green space at roof level in the form of a roof garden. At the same time, thermal insulation is also improved significantly inside the building.
“Advances in waterproofing technology and the increased public awareness of the environmental benefits of roof gardens have led to this particular choice in roof finish to evolve into a variety of permutations. The design of water-wise roof gardens as well as food roof gardens is increasingly popular, with the latter presenting additional socio-economic benefits within the affordable housing market.”
Perrie says the affordable housing market has seen a rapid growth in the specification of concrete roof tiles as the roof covering material of choice. “The timeless aesthetic appeal of concrete roof tiles undoubtedly transforms a house into a home. It requires no additional finish, is labour-intensive, with low-maintenance requirements. The roof pitch enhances interior thermal comfort by encouraging the convectional flow of hot and cold air caused by natural ventilation.
“Whether specifying in-situ or precast concrete as a roof application, the opportunity exists to create shelter that is at the same time both awe-inspiring and sustainable by harnessing concrete’s natural qualities of sculptural flexibility, durability, affordability and thermal mass in conjunction with best practices and quality construction techniques,” he adds.