Mechanical Movement

The use of flexible materials and optimized designs has resulted in much more structural movement under loads, such as wind loading or thermal movement. The bituminous waterproofing membrane has to follow these movements. In addition that displacement will concentrate in small sections of the roofing felt, resulting in very local high deformations.

These deformations are generally recurring. Besides elasticity and elastic recovery, fatigue is very important. The impact of aging should be taken into account when determining its properties.