Flat roofs have an undeniably poor reputation. Everyone knows someone who has a horror story about expensive damage causes by leaks on a flat roof. When you take out a house insurance policy the underwriters will ask about flat roofs too, so it’s natural to assume that flat roofs are risky. But is this really true or has technology moved on?
Old Flat Roof Technology
The issue with flat roofs can be boiled down to two main factors: the design of the roof, and the materials used. Flat roofs are quite obviously flat. When it rains, water can form pools on the flat portion of the roof rather than simple rolling down the tiles into the gutters. Standing water is bad news, and the fact that water hangs around longer gives it more opportunities to cause problems. The other factor is that in the past, nearly all flat roofs were finished in felt, attached to the roof with special tar. This material is great when fixed onto the roof first, but over time will break down in the extremes of the British climate. An old-fashioned felt and asphalt roof typically needs replaced after between 10 and 15 years on your home.
Modern Alternatives to Felt
Most people who have ideas about flat roofs being leaky and problematic are basing them on these old ideas of felt roofs. In the past 20 years however, technology has moved on. There are some modern alternatives to felt which can wipe out at least some of the factors associated with flat roofs. The two new materials which are used most often in roofing are synthetic rubber products known as EDPM and TPO. Unlike felt, these types of rubber are flexible and pliable. They don’t break down as quickly, and come in much larger sheets which can cover the whole roof without joins. EDPM or TPO is attached to the roof in a different way too, and if installed properly can last 25 years, or more.
The one thing the new materials don’t do is address the issue with water standing in pools on a flat roof. If you are in the position of needing to replace a flat roof, ask the roofer if there is anything they can do to build in a very shallow slope. This doesn’t have to detract from the appearance, you just need enough of a gradient to encourage water to roll into the gutter.
Experienced Contractors
If you’re after a long-lasting flat roof, then the new rubber roofing is definitely the way to go. However, a new roof is only as good as the contractor doing the work. Replacing the roof isn’t a cheap job, and it’s worth putting a bit of effort into getting the right people. Get personal recommendations, ask your neighbours, and look on industry websites. Always get at least three quotes and don’t always go with the cheapest one; it might be better to pay a bit more for an experienced roofer with a great reputation.
