Shower cubicles are available as factory-assembled freestanding units or for fitting into corner sites. They usually come complete with shower tray, doors or curtain. Alternatively, you can construct your own from melamine-faced board or exterior grade plywood, panelled or plastered over on the exterior and tiled on the inside to make it waterproof.

1 Selecting the site

Decide on the position of the shower: for a freestanding cubicle, place the shower tray against a flat wall and either surround it with a manufactured cubicle or construct two stud partitions for each side. If you position a tray in a corner, two walls will be 'ready-made' so you can run a curtain around the other two sides of the tray, or install a manufactured corner entry with sliding doors, or construct one more mixed side wall and place a door or curtain across the cubicle opening.

2 The shower tray

Shower trays can be made of cast iron, steel ceramic or reinforced plastic. Plastic trays are inexpensive and lightweight, but they are a little flexible so the edges must be carefully sealed with flexible mastic instead of grout. Trays vary in size so measure the space first to make sure it will fit: they are generally between 750mm (2ft 6in) and 900mm (3ft) square and most stand on the floor with a surrounding apron edge of about 150mm (6in) high. To provide a fall for the wastepipe, some trays have a metal frame to raise it off the floor; others have adjustable feet to level the tray on an uneven floor. A plinth across the front of the tray hides the feet and the plumbing while still allowing access for repairs. A round outlet fits into the bottom of the tray and special shallow seal traps are connected to the outlet. Shallow seal traps are used for both showers and baths, where space is limited. They are fitted in the same way as an ordinary bath waste and, like bath wastes, they must discharge into a yard gully.

3 The partitions

Assemble the partition walls of a manufactured cubicle according to the maker's instructions. Some cubicles have 'lids': it is worthwhile fitting - or making - a lid as these contain steam within the cubicle so it condenses on the waterproof interior walls and not on the ceiling of the bathroom. If you have constructed your own cubicle partition, they should be of melamine-faced boards attached to the stud framework with metal angle brackets, or exterior-grade plywood over which ceramic tiles have been laid with waterproof grout on the inside of the shower cubicle.