After the mastic dries, the roof is covered with roofing material, which is lined with at least two layers. The first layer is called storage, there is no stone crumb on it, but the second layer with the application of such a crumb. All work begins to be performed from the lowest place on the roof of the garage. Such compliance with technology will achieve that the upper sheets will overlap the lower ones, and thereby, the water will not fall under the sheets. After laying a storage layer, material with stone crumbs is applied to it, and with a displacement to the floor of the sheet. So, as a result, you have the seams of the first sheets in the middle of the upper layer of roofing material.
