Shower enclosure installation: fitting a complete enclosure with tray

The enclosure is fitted into a finished bathroom, once the tiling and the tanking are complete. In a renovation, the old enclosure or bath comes out first, the old silicone is cut away, and the fitter checks the condition of the waste pipe and the walls.

The installation itself has these stages:

• Setting the tray on its adjustable legs or on a raised base and levelling it in both directions
• Connecting the trap to the waste and testing it with water before it is boxed in or covered
• Sealing the joint between the tray and the wall with sanitary silicone
• Offering up the wall channels to the edge of the tray, setting them plumb and marking the holes
• Drilling into the tiles without hammer action, filling the holes with silicone and screwing the channels in place
• Fitting the fixed panels and the door, adjusting the hinges or rollers and fitting the seals
• Sealing the channels on the outside, especially the bottom corners at the tray

Silicone needs time to cure, usually around 24 hours according to the manufacturer. The shower should not be used before then.

A classic shower enclosure stands on a tray. The tray can be low profile, sitting almost flush with the floor tiles, or deep enough to bath a small child in. A low profile tray looks modern, but it needs the waste to run low under the floor, or a raised base to give the trap enough room.

An enclosure without a tray stands directly on floor tiles laid to a fall towards a drain. This cannot be added later just by swapping the enclosure. The fall, the drain and the tanking are built into the floor before tiling, and the glass is usually fixed into channels in the floor or into the wall. That is really a walk-in or wet room shower, which is a separate job.

When choosing a tray, it is worth looking at:

• The material, because an acrylic tray is lighter and warmer to the touch, while a stone resin tray is stiffer and quieter underfoot
• The height and position of the waste outlet, so that it lines up with the existing waste pipe
• An anti-slip surface, particularly for children and older people
• Whether the tray and the enclosure come from the same manufacturer and are designed to work together

The best-selling sizes are 800 × 800 and 900 × 900 mm. An 800 mm enclosure feels cramped, especially for a taller person, so every extra centimetre is worth having if the room allows it. With rectangular enclosures, for example 1000 × 800 or 1200 × 900 mm, the longer side is usually where the door goes.

The type of door decides how much space you need in front of the shower:

• Sliding doors take up no space in front of the enclosure and suit small bathrooms
• Hinged and pivot doors need clear space in front of the shower, but they are easier to clean
• Bifold doors fold in on themselves and save space, but they have more joints
• A quadrant enclosure with curved sliding doors takes up the least space in the corner

Before buying, measure whether the door will hit the basin, a radiator or a towel rail when it opens, and whether the boxed panels will fit through the bathroom door and up the stairs.

The simplest case is replacing an enclosure with one of the same size in the same place, where the waste lines up and the walls are straight. The job takes longer mainly because of:

• Removing the old enclosure or bath and cleaning off old silicone
• A waste pipe that does not line up with the outlet of the new tray and has to be moved
• Building a raised base for the tray and tiling its front
• Walls that are out of plumb or a corner that is not square
• Large format or very hard tiles
• A fully enclosed cabin with a roof, a shower panel or massage jets
• Narrow access to the bathroom, which makes it hard to carry large glass panels in

A shower cabin with electrical features, such as lighting, a radio or a steam generator, must only be connected by a qualified electrician. If the water pipes or the waste need moving, that is a job for a plumber before the tiling is done.

A tray that is not level. If the tray is not level, water sits in one corner and the enclosure channels do not line up. The tray is levelled with its adjustable legs or on a raised base and checked with a spirit level before the glass goes in.

A trap that was never tested. A leaking joint under the tray often only shows up months later, when water has soaked into the floor or come through the ceiling below. The trap is therefore tested with water before it is covered, and a raised base needs an access panel.

An enclosure fitted before the tiles. The tiles belong behind the tray and behind the channels. If the enclosure goes in first, water runs behind the tiles and the joint can never be sealed properly.

Silicone in the wrong place. Enclosure channels are sealed on the outside. Silicone on the inside can trap water running down the glass and lead it under the tray. The manufacturer's instructions say which joints should be sealed.

Drilling through the tanking. Every hole in the tiles breaks the waterproof layer behind them, so the wall plugs are filled with silicone before they go in.

Badly adjusted doors. Sliding doors with unadjusted rollers drag and do not seal, and hinged doors swing open on their own. Adjusting the doors is part of the installation, not an extra.

A standard enclosure kit with a tray on legs is manageable for a handy DIYer with a helper and the right tools. Fully enclosed cabins with electrical parts, trays on a built-up base and moving the waste are better left to a professional. Always follow the manufacturer's fitting instructions.

1. Check that all the parts are in the box and that the glass is undamaged, especially along the edges.
2. Set the tray on its legs and level it with a spirit level in both directions.
3. Connect the trap to the waste, run water into the tray and check that the joint does not drip.
4. Seal the joint between the tray and the wall with sanitary silicone and let it dry.
5. Offer up the wall channels, set them plumb and mark the holes.
6. Drill with a tile bit without hammer action, fill the holes with silicone and screw the channels in.
7. Fit the fixed panels and the door with a helper, and never stand glass on its edge on the tiled floor.
8. Adjust the door so it moves easily, lines up and closes properly.
9. Fit the seals and seal the channels on the outside with silicone as the instructions describe.
10. Let the silicone cure before testing the shower.

At handover, look over the shower enclosure carefully and run the shower. Check that:

• The tray is solid, does not move and drains without leaving water in the corners
• The trap under the tray does not drip and can be reached
• The channels are plumb and the glass has no scratches or chipped edges
• The door moves smoothly, does not open on its own and closes properly
• The silicone joints are continuous, smooth and without gaps
• No water escapes outside or under the tray during a test shower
• You have received care instructions and the warranty terms

One simple habit makes the enclosure last longer: squeegee the glass after showering and air the bathroom. It is worth cleaning limescale off the door rollers and seals now and then and replacing worn seals, which can be bought separately.