The best roof, regardless of its shape or color, is the one through which no splash of water leaks. Flat roofs have a higher risk of infiltration because they depend on the tightness of the membranes on a small drainage slope, as well as on the drainage system. The challenges, to which waterproofing membranes are exposed, besides the alternative climatic conditions, can be related to vibration tension, oscillations or periodic movements of the support layer or of the accessible surfaces.
A roof with infiltration problems can look good, because it is not always easy to detect the areas where the water makes its way inside. The affected support layer, with no visible traces of perforations or tears, may present micro-cracks. This defect occurs more often in old roofs or roofs with old insulation materials.
In many cases the weakness of a roof can be solved by a simple surface renovation: a new membrane application over the old one, with small local repairs on the affected areas. The existing waterproofing structure can also be improved with a new or additional layer of thermal insulation.
These repairs must be done in time by a Grade A commercial roofing company to avoid bigger damage (deformations, water between layers, damaged thermal insulation etc.) which will be even more expensive.