Flat roof Types

There are several types of flat roofing, with some that can be further divided into additional subcategories. As time has passed since the first flat roof types were developed, some flat roofs have proven themselves more durable or longer lasting than the others and a favoured few have begun to emerge as modern favourites. Though you might find a range of different flat-roofing materials on larger buildings like flats and office blocks, for the purposes of this article we will mainly be focussing on the types found in smaller domestic applications.

Despite what the name might suggest, flat roofs are rarely flat. They are usually built at a slight incline or “fall”, to allow rainwater (and the like) to drain adequately. For this reason, the materials used always need to be water repellent and water tight. Even with the fall incorporated properly, water pooling can still take place on roofs as they age and slacken, so flat roofs may require more inspection and maintenance than conventional roof types.


The practice of applying asphalt onto roofing has been undertaken for over a century. Layers of fibreglass felt coated in asphalt is brought onto a roof in rolls, before being spread out onto the roof boards and fixed down with either nails or asphalt cement (or a combination of the two). The uppermost layer of the asphalt roll (which must be at least two layers deep) is coated with gravel or stone chips to provide protection from UV light and to act as ballast to prevent the covering from being blown off. This type of flat roofing is the least expensive, but (as a result) requires changing every ten years.

Single ply flat roofing is made from a layer of material with similar properties to rubber or plastics; though still at the lower end of the price range, single ply materials offer a sturdy and energy efficient alternative to roll-out asphalt. The modern materials are favourable to traditional asphalt roll because they are more resistant to mould and mildew formation and require less maintenance. Single ply will usually have a lifespan of ten to twelve years, but thermoplastic polyolefin (TPO) types could last as long as thirty years. The average lifespan of multiple-ply roofs (layers of fibreglass packed tightly between layers of asphalt for stronger reinforcement) will also last between ten and thirty years.

Modified bitumen may be used to coat the outer-layer of some multiple-ply roofs, applied in a thin membrane and composed from a combination of polymers and asphalt (bringing the best of both worlds together, though not necessarily with the best results). A modified bitumen roof will only have a lifespan of between ten and twenty years, but is likely to require less maintenance than a standard multiple-ply roof with a regular asphalt coating. Flat-seemed metal roofing are the longest lived of all the roof types, lasting for between twenty and fifty years, but are also the most cost effective.

If you have a flat roof you are likely to have difficulty finding flat roof insurance, because insurers see them as being a non-standard insurance risk. When insurers refuse to offer you the flat roof house insurance you require, you should be able to find cover from a non-standard home insurance provider. With HomeProtect insurance you can get a competitive online quote for flat roof home insurance, regardless of what type of flat roof you have.