How To Install a Toilet

The location of a toilet in your home is restricted by the need to use a 100mm (4in) soil pipe which has sufficient fall to discharge into the stack. However, it is possible to install a small-bore waste system, often called an electric toilet. These have an electric pump and a shredder allowing waste to be discharged into a 22mm (3/4in) pipe up to a distance of 50m (55yd) from the soil stack. This means that they can be installed in small spaces (under the stairs or in cellars) because they can pump vertically up to a maximum of 4m (4yd), so long as the space is adequately ventilated and the system has been approved by the local water authority. It must be wired to a fused connection unit – or via an approved flex outlet if fitted into a bathroom.

In an electric toilet, the shredding unit fits neatly behind a conventional ‘P’-trap lavatory pan. The system is activated automatically by flushing the cistern and switches off about 20 seconds later. For safety, the system should be wired to a fused connection unit.

The small-bore wastepipe from the toilet must be connected to the soil stack at least 200mm (8in) above any other waste connections. It can be connected to the stack using a standard 36mm (1 1/4in) waste boss but it will require a 22-36mm (3/4 – 1 1/4in) adaptor.

Step by Step Instructions

1 Construct framework

An unattractive cistern and ugly pipes can be concealed behind a ‘box’ with removable panels and a lid, providing additional storage and easy access in order to carry out plumbing repairs. Measure and cut timber for a framework and fix securely to the floor and walls. Use a spirit level to check alignments.

2 Make three panels

The front of the box is constructed of three separate and removable panels. You can use TGV, or sheets of hardboard or ply. Measure and cut the TGV, assemble using wood adhesive and attach a small supporting batten to the reverse. Use a nail punch or a hammer to drive home the nails.

3 Cut hole for wastepipe

The central panel needs a hole for the wastepipe. If you are using TGV, make the central panel in two sections and cut a matching semi-circle in each and assemble it around the wastepipe. If you are using boards, you may find it easier to use only two panels and cut the hole for the pipe where they butt together.

4 Fix the central panel

The central panel, which accommodates the wastepipe, is fitted first. Mark the position of the drill holes. Use quality screws so they will be easy to undo if you need to disassemble the box. Next fit the panel furthest from the flush lever.

5 Position final panel

Offer up the final panel. It will stand in front of the others until the flush lever is removed. Mark the position of the lever on the panel and drill a small hole to accommodate the arm of the flushing lever.

6 Replace flushing lever

Remove the flushing lever from the WC. Bring it forwards on its connecting arm and replace it through the panel. In most cases there is enough length on the arm, but you may find you have to replace it and the lever with a new one.

7 Make a template for the lid

If the ‘lid’ area is simply rectangular, measure the length and width, check the angles at the corners and cut a lid from a sheet of board. More complex shapes are easier to cut if you make a template out of stiff card. Do not fix the lid permanently – you’ll need access to the cistern beneath.

8 Finishing

With the ‘lid’ in place, the box is ready for finishing. The front edge of the lid can be finished with a strip of quadrant moulding and the ‘box’ painted, stained or varnished to complement the surrounding decor.

Tips and Tricks – Panelling

  • Place a rolled-up towel between the frame and the cistern to absorb vibrations when you screw the panels in position.
  • Don’t force the panels into position: if they fit too tightly, plane down the edge nearest to the wall. Any smal I gaps can be disguised later with a strip of moulding.
  • Periodically take the lid off the box and check that all is well in the cistern. Remove a panel to check for any leaks from the seal on the overflow.
Back to Top