Concrete, one of the world’s most widely used building materials, is not only a particularly durable material but also provides effective sound and thermal insulation. Hanlie Turner, marketing manager at the Cement & Concrete Institute (C&CI), says noise can be described as unwanted sound. “When sound waves strike a barrier such as a wall or floor, the waves are reflected, absorbed or transmitted in varying degrees, depending on the form of the barrier and the material in which it is constructed.
To control the transfer of noise between rooms and to limit external noise from the interior, the barrier must have good sound insulating properties. Generally, the heavier the material, the better – and that’s why concrete is an excellent material for sound insulation.”
Turner says that shrinking building site sizes, especially in housing developments, have resulted in houses being closer together and the transfer of noise between houses is therefore greater. “Noise – such as that emanating from increasing traffic volumes – is more easily excluded by a concrete or concrete masonry structure than by lighter materials. The technique of providing sound insulation by using heavy walls between rooms is as valid in insulating a house from external noise, even if it is a bit more difficult to achieve in outside walls with their windows for light and ventilation. However, to help reduce the amount of noise reaching these openings a concrete or concrete masonry wall on the property boundary will cast a ‘sound shadow’.”
Regarding thermal insulation, careful design can ensure that concrete and concrete masonry walls absorb and store the heat of the winter sun by day to warm the cooler nights, while in summer the same walls, if shaded by eaves, keep the house cool. In this way, concrete and concrete masonry walls help to maintain interior temperatures at comfortable levels throughout the year.
“The mass of a concrete internal wall is just as important for passive solar design as it is for sound insulation. Combined with appropriate building orientation and effective roof insulation, concrete masonry walls, with their high thermal storage capacity, can even out the effects of outside temperature fluctuations. As a result, comfortable inside temperatures are achieved with minimal use of heating or cooling systems, so reducing energy costs.
“Concrete roof tiles also have good thermal insulation properties,” Turner adds, “and they are more affordable than most other roofing materials.”