Leading Australian roof tile manufacturer Bristile Roofing conducted an experimental study to disprove the common misconception about the porous and water penetrable properties of concrete roof tiles.

Bristile Roofing’s investigation into the permeability of concrete roof tiles has yielded important results for homeowners and the building industry by shedding light on this long held myth. 

To determine whether water could penetrate concrete roof tiles, 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.

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. 

Following the test, the underside of the tile was observed to determine if there had been any water penetration. It was confirmed that there was none. 

Marketing Coordinator at Bristile Roofing Mr Michael Monro comments that the study has improved their 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. 

According to Mr Monro, another common fallacy surrounding roof tiles is that they absorb significant amounts of water during heavy rain, which is again not true. Tiles manufactured in accordance with the current version of AS 2049 Roof Tiles cannot absorb more than 10% of their own weight in water after total immersion in water for a period of 24 hours.

Concrete roof tiles deliver multiple benefits to homes including long-lasting durability, low maintenance requirements, and natural density that makes them ideal for both acoustic and thermal insulation. Additionally, 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.

Mr Monro observes that 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. 

Following this study, Bristile Roofing hopes that consumers will be able to make a fully informed decision and that fewer will be misled by dubious claims often used to encourage homeowners to re-roof or re-colour when there is absolutely no need.