Connecting a Spray Bidet

Before buying a spray bidet you should check on the regulations of your local Water Authority to make sure that the plumbing system of your home complies with these regulations, or can be made to do so. In all probability you'll need to run a separate cold water supply pipe from the cold water storage cistern to the bidet.

You're not allowed to run this branch from another cold water distribution pipe, or to make a direct connection from the main. Similarly the hot water supply to the bidet must be taken by a separate distribution pipe from just above the hot water storage cylinder and not as a branch from the existing bathroom hot water supply pipe.

A further requirement is likely to be that the base of the cold water storage cistern must be at least 2.75mm (9ft) above the level of the bidet inlet - a rule that could involve you in raising the position of your cistern.

While ordinary basin taps can be used for over-rim bidets, a special mixer with a diversion valve and a supply pipe to the spray must be fitted into a spray bidet. These mixers often incorporate a pop-up waste which enables the waste plug to be raised and the bidet emptied by pressing a control knob which is part of the mixer and diversion valve mechanism. This kind of bidet is normally sold with mixer, spray and pop-up waste already fitted.

Dealing with the waste water

The waste water from a bidet must run through a trap. If your house has a single stack drainage system this should have a deep seal of 75mm (3m). With the older two- pipe drainage system a shallow seal of 50mm (2in) is permissible.

If you've got a single stack system you'll have to run the branch waste from the bidet and connect it into the main stack. And you'll have to follow the district or borough council's requirements regarding the gradient of the branch waste pipe and how the possibility of it being fouled by the discharges from the WC can be averted.

If your house has a two-pipe drainage, system, then it's important to remember that a bidet is a waste and not a soil appliance, so the waste water can be run into an open gully.