A like-for-like replacement does not usually need planning authorization. Simply replacing your old flat roof with a new one should be a very simple task. When changing a flat roof to a pitched roof, planning authorization may be required. The reason for this is that the pitch of the new roof needs to match the height of the existing roof. If it doesn't, then water may be able to run under the new roof where it won't be seen or felt by anyone living in the property. The best time to replace your flat roof with a new one is before the next big storm hits. This way you will not have to worry about any damage being done while you are away and you will also know that your new roof is going to be installed properly. If your current flat roof is more than 10 years old then it's time to replace it. Older roofs tend to be less effective at protecting your home from rain and snow due to holes in the surface or problems with the membrane. They may also be leaking internally which can cause serious damage to your flooring and other parts of your property. There are several different materials used in the manufacture of flat roofs, such as metal, plastic, and rubber. Each material has its advantages and disadvantages. For example, metal roofs are strong and durable but they are also heavy and expensive.