All the outlet pipes from drainage fixtures in buildings (washing machines, showers, toilets etc.) are connected to the sewer, forming a linked pipe system. If the wastewater cannot flow freely through the sewer e.g. after heavy rainfall or due to blockages in the sewer pipes, it is pushed back into the connected outlet pipes and can flood all the areas of the house which are below the backwater level, including any fixtures and furnishings etc.
Backwater is always possible
For economic reasons, mixed public sewage systems often cannot be dimensioned in such a way that they can deal with extremely heavy rain without any problems. For this reason, flooding of the sewer and backwater in all connected pipes must be expected during heavy rain.
In addition, backwater can occur for the following reasons:
- Blockage, burst pipes or damage to the sewage system.
- Pump failure, if the drainage system is connected to a pumping station.
- High water levels in the recipient (stream or river), since rainwater cannot flow away easily from low ground.
- Pipe blockage or diversion due to repair work.
- Increased wastewater feed, for example when sewage systems are being rinsed, the fire brigade is in action or more pipes are connected to the sewage system than originally planned.
Installation possibilities
Exposed installation
Ideal for the renovation of old buildings which are in danger of backwater – the low-cost, clean and standard-conform solution for retrofitting backwater units. To avoid the complete wastewater pipes having to be rerouted in expensive construction work, Eurodrain recommends installing the central backwater protection unit in the existing exposed wastewater pipe. This guarantees free access to the backwater unit for maintenance work and pipe cleaning.
Installation in a concrete floor
The convenient, practical and attractive-looking version for new buildings creates additional accommodation space in the basement. High land prices often force clients who build a house on a small plot of land to use rooms in the basement to maximise the accommodation area. In addition, toilets, showers or utility rooms are often located in the basement.
The backwater protection unit is installed concealed in the floor. The easy-to-install set with a cover that can be tiled over as required can be used with a wide range of different interior styles and trends – whether the room in question is a music room, home office or sauna and spa.
Covers with a drain function for additional surface draining in an emergency (e.g. if the basement is flooded during heavy rain) provide even more safety. A special sealing set protects the basement from water pressure from below.
Underground installation
Up to now, products protecting against water penetration have mainly been installed inside buildings. In the meantime, however, new methods are available. For this, an inspection chamber is installed in front of the building where the backwater flap is installed.
If wastewater occurrence increases, the correct backwater protection unit can always be retrofitted e.g. when older residential areas are expanded or extensions are built on houses to cope with increased demand. This means clients and the local authorities are always on the safe side.
Equally, pumps and sewage lifting stations which so far have taken up a lot of space in the basement can now be installed in the chamber. Outside the building, they run quietly and reliably, and are easy to service.
KESSEL offers a number of backwater valves to solve this problem. These include
- Premium backwater valves with mechanical or motor-driven backwater flap and pump for draining wastewater with sewage, even during backwater.
- Classic backwater valves with mechanical backwater flaps for protection against backwater.
- Backwater valves in chamber for underground installation. Frees up basement space by moving backwater protection to outside the house.
KESSEL backwater valves are available from EURODRAIN in South Africa.