The connection for the washbasin consists of three openings


The connection of a washbasin normally consists of three components. Two supply lines provide cold and warm water and the drain disposes of the used water. For perfect operation, cross-sectional values ​​of the pipes must be observed, drainage angles must be maintained and a siphon installed for odor protection.

connection triangle

In most cases, the connections in the walls of bathrooms are walled and run in a standardized position. The three connections are placed in an upside down triangle shape in the wall. The two upper corners supply water and at the bottom corner is the drain. The following dimensions are considered as standard:

  • The height from the floor to the middle section of the drainpipe is between fifty and 56 centimeters.
  • The upper two inlet openings are located at a height between 56 to 64 centimeters.
  • The distance between the two inlet openings is between eight and twenty centimeters.

These predetermined dimensions determine when mounting the washstand and connecting the required components and mounting method.

standard dimensions

Even with different washbasin sizes, the connections for the basins and fittings do not change. Therefore, the height must always be adjusted when planning a washbasin. If extraordinary dimensions are required, the connections must be adjusted or offset on site.

The cable cross-sections are also subject to standards that ensure adequate and sufficient inlet and outlet. Internal cable diameters are scaled in nominal size DN. For the supply of hot and cold water, the diameter is 15 DN, which corresponds to half an inch. The drainpipe needs a diameter of forty or fifty DN (1.5 or 2 inches).

Components and space requirements

Angle valves are screwed onto the two supply lines, onto which supply hoses are attached to the valves. The hoses must be mounted with motion tolerance to accommodate final assembly and heating expansion.

When planning the dimensions of the washbasin and / or installing a vanity unit, the odor control must be taken into account. It consists of a curved tube and simultaneously acts as a coarse dirt filter.

Tips & Tricks

Correspondingly prepared drainpipes have a diverter which has a mounting socket for connecting the drainage hose for a washing machine. Also think of a branch for the cold water inlet.


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