Maintenance on any roofing product is key for life expectancy. Flat roofs especially mastic asphalt, has always been targeted as problematic. Here are some reasons why, life expectancy does not always mean problems lie with the mastic asphalt roof. Coping stones regularly occur on flat roofs, all should have a DPC under the stones to stop dampness appearing.
Many of the older flat roofs not always had a DPC so when there was a breakdown of the mortar between the stone joints, ingress would happen, thus the mastic asphalt would take the blame. Lead Flashings dressed to a mastic asphalt roof also give problems. Mortar that is pointed to the lead flashings often break down and the weight of the lead pulls from the chase, now exposing a void between the asphalt and the wall, causing ingress, the asphalt roof gets the blame.
Many new roofs have air handling units positioned around areas for air condition, tradesman work around these for maintenance unaware that oil damages asphalt, so when problems occur, mastic asphalt gets the blame. So, for we have not addressed the mastic asphalt life expectancy. These are just a few of the problem that happen during the life of a flat roof which are taken out of context. 25 years should be the minimum before any problems arise with a mastic asphalt roof. With regular maintaining annually and solar reflective painting every 3-4 years, a mastic asphalt roof will give longevity far beyond the recommended guarantee.
For more interesting information about mastic asphalt please read more of our blog posts. An index of all our blog posts covering all aspects of asphalt can be found by clicking on the following link: Mastic Asphalt Blog.