For the readers that are the architect, the design and imagination to the house or building are limitless. However, the reality is the only one thing that hold you back which you never deny. This contradict situation can be seen in every architecture element, especially the “Roof”. The roof can be designed but it might never built since the construction and maintenance of the roof can be too difficult, too expensive and too much to handle. In this case, the flat roof would be one of the first in this “too much” list.
The flat roof was created in just around century. The first modern residential flat roofs began appearing in the early 20th century by men like the Austrian Adolf ("ornament is crime") Loos, who designed white, flat-roofed cubist houses. Then the modernist masters including Le Corbusier, Mies van der Rohe, Walter Gropius, and their contemporaries expressed their idea of modern architecture in different forms with one common – the flat roof design. The most noticable architecture that represent those era such as Corbusier's Villa Savoye, built near Paris in 1929, and Mies's Barcelona Pavilion from the same year. They were the demonstration of how beautiful flat-roofed buildings could be, and had been widely copied and adopted all over the world.
In Thailand, we have seen the building with flat roof for many decades all over the country. From the most sophisticate architecture to the layman's shophouse, the flat roof was applied as the common type of top-covered plain for the building. Not only it's look of modern, the flat roof also provides more usage and space for the building owner where the land is scarcity. As mention above, there are a lot of problem when considering to have the flat roof. And with the severe weather of tropical monsoon region where rain and sun can come within 5 minutes as this country, those problem seems larger and different than what American and European practice could handle. These problem included the leakage, the water run-off, the heat, the durability and what ever you can think of.
The most typical problem of the flat roof as I witness to my client's and friend's properties are the water leakage. But the leaked water can damage the building and it's inside much more than you can imagine. The water not only destroy your beautiful interior and decoration such as wood floor, carpet or cabinets. Also The water can also damage the electric appliances and system, as well as the building structure in the long term.
Most of the water leakage problem caused from the roof construction. Sometimes, the leakage caused the sagging in the middle of old or poor built flat roof which allowing rainwater to pond in that sag area, then the water will penetrate through any tiny pin hole it can find.
Eventhough there are several technologies and products that help but the best way to avoid the problem is to design and construct the flat roof carefully. The designer must understand the nature of the water which always come down to the lowest point as possible. The proper gradient of to allow rainwater run-off and the number of the roof drainage and downspout must be calculated to handle the heavy rain in the monsoon season. The flat roof must be covered or appled the anti-leakage coating or ever covered with the materials such as the torch-on flet or PVC membrane which is clean but more expensive.
The cover material for the flat roof,especially a concrete can be found in any Home Pro or building supply shop. However, you can try call the experts or the producers of the roof covering material from the design stage and let them come to present their product and application so that you will understand the technologies. Those expert also able to give you an idea of the foreseen problem after the building finished and occupied by the owner so that you can prevent it by the design. Moreover, you can estimate the cost of constructing and treatment of the flat roof and tell the owner for the budget which I believe, a lot cheaper than fix it when it leaks.
As mention earlier that imagination and reality might not be the same, but with the good under standing of technology and product knowledge, both of them can meet in the best way and create the modern look of the building even in it was built in this part of the world.