Modified rolled materials for roofing are produced of reinforced base (Fiberglass mats, glass fabric or polyester), bitumen and polymer modifier.
While choosing the underlying material, keep in mind that fiber cloth has high tensile strength, polyester has much better specifications but is also much more expensive. Its durability is similar to that of glass fiber, but with stretch ratio 10-25 times higher. Thus, polyester can withstand loads without base deformation.
Face surface of rolled materials meant for upper layer application is covered with coarse-grained or flake-like surface dressing, ensuring protection from the sun and air oxygen. The following materials can be used as surface dressing:
- sand;
- schist granulate;
- mica-vermiculite;
- aluminium or copper foil.
The bottom surface of the upper layer, and both surfaces of the underlying material should be secured from adhesion by application of fine-grained sand or powdery surface dressing. Low melting polyethylene film is applied for melting materials.
In general, rolled materials are various but the main differences usually concerns the kind of base and the type of modifier.