A Flat roof system, or more simply referred to as a flat roof, is a design for the roof of a house or building which goes against the typical Western World style. Rather than having a roof with a noticeable slope to it, a flat roof, like the name suggests, is completely flat. Despite logic suggesting that this is a bad idea, the system has many unexpected benefits.
Flat roof systems were originally developed in the arid climates of the Middle East. In such climates the problems of a flat roof, namely a build-up of snow or the stagnation of rainwater, are non existent. For the same reason, similar roofs were developed in the original adobe houses or the American Southwest and Mexico.
The immediate benefits of having a flat roof system are its cost efficient use of available space. With a traditional roof, the angular slope means a great deal of unusable space goes between the ceiling and the surface of the roof. This is what we typically call the attic. On a flat roof you make the maximum use of space below the roof. Also because the roof is flat, you can use the space on top of the roof as well. Recreational roof gardens and other such things are common uses for the newfound space. It also makes the installation of solar panels much easier.
There are several risks and drawbacks involved with having a flat roof system. The biggest problem is that flat roofs do not reflect heat very well. This means that your house will be sweltering in tropical summer if you live close to the equator. Thankfully, new coatings have been developed which can remedy this problem. The other risk is the potential for leaking. Such roofs do not use overlapping shingles; as such, they rely on one or multiple layers of solid materials to maintain their integrity. If the layers were to crack or a small hole would develop, it would be immediately noticeable and a considerably bigger problem than a leak in a traditional roof.
There are multiple flat roof systems that utilise different construction materials. Asphalt roofs are the most common, using multiple layers of gravel and tar to create a surface similar to that of a road. Unfortunately, like a road, they become brittle in the heat and develop cracks very easily. Thankfully new more effective materials have since been developed. These materials are liquid polymer composites which either develop a rubberlike seal over the roof or never entirely cure, meaning they will never dry out and crack.
The biggest misconception about flat roof systems is brought on simply because of their name. Flat roofs are not perfectly flat. Typically a flat roof will have one side an inch or two higher than the other. While this is often not noticeable to the naked eye, this creates a gentle slope of a few degrees. This slope is generally sufficient to prevent rainwater from pooling on the roof.