The base which is designed for single- or multi -layers roof covering with the use of membrane must fulfil the basic requirements. It must be tough and stiff so that it ensures the move of load during the building work and also in the general use of the roof. The base must be flat, which influences the right flow of water, good adhesion of membrane and qualities of good workmanship of the roof covering. The base has to be cleaned of dust and all impurities, and grounded with proper, for that basis, primer product. All the passages from horizontal into vertical insulation nearby chimneys, attics and other elements on roofs, should be moderated with the use of polystyrene wedges.

Concrete base

It must be stable, before starting the work its humidity cannot exceed 5%. On the base the dilations must be done so that it will be divided into fields of shape and sizes right for the construction of that particular roof. Dilatations in the base should be treated properly.

Wooden base

Made of boards, plywood or chipboard, the thickness depends on the gauge of rafters, providing the stiffness, but not less than 22mm. Humidity of boards, beams and laths, used for making the roof on which the paper is laid, cannot exceed 22%.

The base of thermo-insulating boards

The base ( well-matched material for this kind of roofing) must be characterized by the right durability - density and compression strength. Thermo-insulation made of tough boards: mineral wool, polystyrene, mineral wool covered with bitumen, polystyrene laminated with bituminous paper.

The base of existing membrane layers

In repairing the old roofing it is necessary that the base must be dried and all bumps smoothed. In the areas of defects one or more layers of paper should be welded or a filling mass should be used and then the whole roofing should be protected with a roofing cure agent. In case of finding high humidity of the existing covering (over 6%), it is necessary to provide the ventilation of this roofing by using ventilating membrane PP50/700 and ventilation chimneys ( 1 by about 40m²) – SYSTEM 05 and SYSTEM 06. In the base some holes can be made, about 8 by 1m² in order to drain the humidity off the existing roofing. The use of ventilating roofing will allow carrying the humidity (vapour) through the ventilation chimneys without bubbles.