The pump shaft in the basement

What is called a pump pit for a basement is nothing more than a pump sump. In the pump shaft, the water collects from different "Sources " and then pumped off a submersible pump. Below you will learn everything that is related to a pump shaft in the basement.

Tasks of a pump shaft

First of all, it must be distinguished afterwards, which is why a pump shaft should be installed. There are basically two different possibilities:

  • Also read - the water pump for the basement
  • Also read - the wastewater pump in the basement
  • Also read - Build pump shaft yourself
  • To dewater the cellar
  • For pumping wastewater in combination with a lifting system

Draining the cellar

Pretty much throughout the 20th. For the century, the black tub was the usual construction, in which a cellar was built. The basement walls are sealed with bitumen. This is where the term "black basement tub " is derived.

White and black basement tub

Opposite is the white basement tub. This is made of waterproof concrete (waterproof concrete) and designed as a tub, so it is absolutely tight. In the meantime, more and more architects and building consultants are recommending the white bathtub as a building standard. Nevertheless, some builders still save here (unfortunately at the wrong end).

Particularly effective for basement drainage

In order to get a cellar dry or to be able to keep it dry, a pump shaft is created, which is excavated in the cellar floor. Water always takes the path of least resistance, which is why it seeps through the pump shaft. If a certain height of the water column is reached, a submersible pump located in the shaft (27.34 € on Amazon *) (these are centrifugal pumps - here the function of a centrifugal pump) switches on and pumps the water out.

Pump shaft for a lifting system

Cellars are often below the canal level. There is also the backflow level, which is completely missing in many cellars. This is the amount of wastewater in the sewer that would be required to exit at the lowest connection point in the house.

Extended use of the cellar with lifting system

If the basement is not used appropriately (no washing machine, no toilet, no wash basin, etc.), the deepest connection point would be on the ground floor. The backflow level is from the sewer level to this connection point.

The backflow level

So that sanitary facilities and washing machines can also be operated in such a basement, the wastewater must be discharged into the sewer above the backflow level. Otherwise it would come under certain conditions (rain. Snowmelt etc.) quickly to flooding in the basement.

So the wastewater is "lifted " above the backflow level, which gives the lifting plant its name. Now, however, not even the smallest amounts of water can be pumped out efficiently. Therefore, the wastewater is first collected in a pump shaft. When a certain height of the water column is reached, a float on the pump usually switches it on.

Lifting systems for gray or black water

Now, however, a distinction still has to be made between lifting systems for black and gray wastewater. Gray water is waste water from washing machines, sinks, showers and bathtubs. Black water, on the other hand, is sewage mixed with faeces (and in some cases other solids).

Black water lifting systems always a closed system

For odor reasons alone, this black water is lifted in closed systems. As a result, the pump well is a plastic container that is sealed. A suitable filter system (activated carbon) is used for ventilation (depending on the wastewater level). In addition, there is also an integrated cutting unit that shreds all solids to a certain size.

Gray water lifting systems should work in a closed system

Pump shafts made of concrete are often considered for lifting systems for gray water, as well as for a pump sump for basement drainage. However, unpleasant odors can arise here, which is why we generally recommend a closed lifting system. By the way, here you can find out what can be the cause if the concrete pump sump stinks.

Tips & Tricks All pump shafts in the house must be laid out in such a way that there are no discharges from outside - for example from the drainage.

In addition, some inexperienced architects repeatedly recommend a pump shaft for a white basement tub if the basement is lower than the sewer system. Any deviation from a straight surface means an angle, etc. This increases the risk that there will be leaks in the white tank because the deeper shaft is not poured in one pass with the base plate. When building a new building with a base plate, you should carefully consider whether a pump shaft should actually be installed. There are also systems that raise sewage above the level of the floor slab.

The terms black and gray water were introduced in order to be able to precisely name the management of such wastewater in a building. With the increasing popularity of domestic sewage treatment plants and separate collection or. Separation of urine (ammonia as a valuable raw material for fertilizer), black water is also divided into brown and yellow water.