One problem with maintaining flat roofs is that if water does penetrate the barrier covering (be it traditional or a modern membrane), it can travel a long way before causing visible damage or leaking into a building where it can be seen. Thus, it is not easy to find the source of the leak in order to repair it. Once underlying roof decking is soaked, it often sags, creating more room for water to accumulate and further worsening the problem.
Flat roofs can become troublesome if they are old and many people resort to temporary patch-up measures to prolong the life of their flat roof. This often leads to weaknesses and problems further down the line if not carried out with complete confidence and expertise. McCann Roofing has extensive experience of the various flat roofing techniques and will be happy to explain these to you if you decide to get in touch. In 2014 Mr McCann became qualified in the [ GRP] technique and also has a reliable and experienced flat roof associate on board in order to provide the best possible service.
Don't resort to patching up that flat roof again and again.