ACO Gravity drainage
Flat roof gullies for gravity drainage are always used for draining small flat roofs with a surface area of less than 150 m2 per gully. But this kind of drainage can also be used for larger roofs too. Whether the roof covering is a membrane, concrete or gravel: ACO Spin flat roof gullies can be flexibly adapted to the different requirements. The individual components of the gullies such as gratings, top sections and gully bodies can be combined as needed using our building block system.
With the correct accessory components the ACO Spin flat roof gullies can also be used to drain green roofs. Given increasingly dense construction in towns, more and more ecological surfaces are being sealed over. With an intensive or extensive green flat roof it is a relatively simple matter to compensate for this.


The roof forms the upper boundary of a building. The roof seals are very important because of the severe stress the roof is exposed to from precipitation, strongly fluctuating climatic influences, and a whole range of traffic loads and stresses.
Roof structures can therefore be divided up into two groups depending on the seal:
- Flat roof structures with one seal
- Flat roof structures with two seals
The Spin flat roof drains can be used in all types of roofs thanks to their modular system. In roofs with two seals, the drain body is integrated with the vapour seal, whilst the riser is in incorporated in the roof sealing membrane.
The drains are fitted with compression sealing flanges which allow them to be integrated within all standard sealing membranes. The drain bodies are installed in special insulating bodies to prevent the formation of of condensation water around the drain body – this is particularly important for thermally-insulated flat roofs, green roofs and parking decks.
- Planning must comply with EN 12056-3, as well as the flat roof regulations and, where applicable, the green roof regulations.




Flat roof drainage systems must always be laid out in accordance with the reference rainfall figures. The reference rainfall can be exceeded during periods of heavy rainfall. This can cause water to pool on the surface of a flat roof. An independent emergency drainage system for flat roof drains is therefore required in accordance with EN 12056-3.

