Flat roofs; roofs with no pitch, are very common on industrial and commercial buildings although they are also used for residences. Speaking from a purely architectural point of view, a roof with a slope makes a great deal of sense; rain, snow, debris, etc will simply travel down the roof in the direction of the gutters and be carried away.
Flat roofs have poor water flow:
Water will not flow on a flat roof; hence flat roofing in St. Louis needs to have well designed drainage and gutter systems, controlling the disposal of water on a flat roof is far more difficult than a roof with a slope. When water cannot be eliminated from a flat roof, there is going to be trouble, trouble that will be costly to correct and potentially very damaging to the building interior.
Why does a flat roof leak?
Other than very small flat porch roofs, flat roofs have seams which are held together by adhesive. After a number of years exposure to the elements the adhesive breaks down and begins to crack. This tendency is accelerated in the US mid-west where there are dramatic temperature differentials over the span of a year.
Another problem is condensation that occurs under the covering. During the winter months the condensation freezes, expands and the result is a broken seam. Excessive heat is just as problematic, in the summer months the condensation expands; the result is bubbles forming in the membrane.
Although there is little that can be done about the weather, there is something that can be done about the third cause of flat roof damage; poor construction. The installation of different types of flat roofing in St. Louis requires totally different processes. The primary problem is the proper selection and application of the adhesive and to ensure the roof structure is well built.