New Research Sheds Light on the Permeability of Concrete Roof Tiles

New Research Sheds Light on the Permeability of Concrete Roof Tiles


Investigation into the permeability of concrete roof tiles has yielded important results for homeowners and the building industry by shedding light on the long held misconception that concrete roof tiles are porous and penetrable by water.

Leading Australian roof tile manufacturer Bristile Roofing set out to dispel this myth by conducting an experimental study aimed at determining whether water can, in fact, penetrate concrete roof tiles. For this investigation, a test was set up to measure permeability to a higher standard than that set out in Australian Standard AS 4046.5-2002 Methods of testing roof tiles - Determination of Permeability, to which all manufacturers in Australia are required to adhere.

The study used a ”clean skin” tile without any applied surface coating, which was secured approximately 10cm from the base of a purpose made steel tank, with the edges sealed using silicone to ensure water tightness. Water was then poured on top of the tile and left for 48 hours, a significantly longer period than the six hours required by the standard. At this time the underside of the tile was observed to determine if there had been any water penetration, none was observed.

Commenting on the findings, Marketing Coordinator at Bristile Roofing Mr Michael Monro stated, “This research has improved our understanding of the permeability properties of concrete roof tiles and confirms that even without any colour coat or sealant a concrete roof tile manufactured in accordance with the relevant Australian Standards is not water permeable, even in extreme conditions that are unlikely to occur naturally.”

Michael also said “Another common fallacy surrounding roof tiles is that they absorb significant amounts of water during heavy rain which is in fact not true. Tiles manufactured in accordance with the current version of AS 2049 Roof Tiles can’t absorb more than 10% of their own weight in water after total immersion in water for a period of 24 hours. Bristile Roofing product routinely performs better than the standard.”

Mr Monro added, “The roof is one of the largest external surfaces of a home and for this reason, understanding the properties and benefits of each roofing material is critical when re-roofing or undertaking a new build. Bristile Roofing hopes that with this research, consumers will be able to make a fully informed decision, and that fewer will be misled by dubious claims often used to encourage home owners to re-roof or re-colour when there is absolutely no need.”

Concrete roof tiles offer a multitude of other practical benefits including durability, low maintenance requirements and natural density which makes them ideal for both acoustic and thermal insulation. When outside temperatures are fluctuating, the thermal mass of roof tiles reduces inside temperature extremes by absorbing thermal energy and releasing it later when the surrounding atmosphere is cooler.

To find out more about the full range of Bristile Roofing products, please visit www.bristileroofing.com or call 1300 274 784.