Are Mineral Toppings of Asphalt Roofing Sufficient to Protect Flat Roofs and Roofing Felt Alone?

Abstract

Mineral surfaces are an integral part of bituminous roofing felt. Their task is to protect less resistant elements from the destructive effects of the environment. Since the first application in 1897, they have been constantly improved in the direction of better functionality and aesthetics. It often turns out that the intended effect has not been achieved. During the first years of operation, there are signs of roof damages on most facilities. Due to the complex interaction of roofing elements, several causes of damages can be defined. A group of processes taking place in mineral roofing toppings is important for roofing felt. Mineral surfaces are exposed to physical, chemical and biological factors. They cause losses due to the unavoidable breaking of adhesion to the modified asphalt. Pulling out caused by factors occurring on the roof is a long-term process with more effects on the covering, in particular its durability and tightness. In the paper, the reasons for the release of mineral topping from the SBS modified asphalt layer were defined. The analysis shows that as a result of significant degradation and harmful impact of mineral coverage, this layer may lose the ability to protect the roofing paper, and long-term changes threaten the durability of roofing materials. Solutions have been proposed to significantly reduce the phenomenon caused by specific factors.

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