The base (screed) serves to ensure a flat and strong surface under the roofing carpet, as well as reducing the influence of deformation efforts on it caused by a change in the temperature of the outer air. It is usually made of a layer of cement mortar of the brand 75-100. In order for the screed to perceive stretching efforts that occur with changes in the temperature of the outdoor air, it is recommended (especially in areas with continental and climate) to reinforce a wire from a wire with a diameter of 2 mm with a cell size of 200 x 200 mm.