ISOLINE ONDUTILE underlay sheets are used as a secured waterproof layer designed to be fitted under a traditional tile or slate roof. This solution is a perfect waterproof barrier against potential water ingress that may happen over time through a breach in the primary roof covering.
Perfect waterproofing under concrete, slate or clay tiles for very low-pitched roofs with BBA accreditation.
Bitumen is also one of the most well used raw materials in the roofing industry, thanks to its perfect sealing performance. Cellulosic fibres derived from wood give the Onduline roofing sheets their mechanical strength.
The Onduline roofing material is manufactured using 50-60% recycled cellulose fibres, so is also good for the environment.