Roof Drainage Design

For smaller surfaces gravity drainage systems are the ideal solution.

Roof drainage design.

Hence this is by far the most common roof drainage situation. The main benefit of inner drains is that the system is hidden from view. Most flat roofs suffer from poor drain locations or drain levels that are high. Aco offers functional solutions which are specially designed for flat roof areas and which ensure the water is drained effectively.

On many occasions drains are too high and water cannot flow off. When designing a roof it is essential to pay close attention to where the drains are. For larger roofs siphonic drainage systems should be installed. Inner drains are resistant to freezing but can require careful maintenance to prevent problems.

These drains are distinguished by having higher rims. In either case the discharge shall be located so that it is readily visible by building occupants. Secondary or emergency roof drainage is required wherever the buildup of water is detrimental to the roof structure. As we will see in steps 3 4 the size of the roof drain lines is dependent on the square feet of the roof area being served by each roof drain.

One gully can drain at least 150 m2. For most dwellings you ll find that gutters range in size from approximately 100mm diameter to 150mm diameter assuming gutters with a half round section profile and downpipes range from approximately 60mm diameter to 90mm diameter assuming circular downpipes. Having sufficient drainage on a flat roof is vital.