Shower screen installation on a tray or bath

In a renovation the first job is taking out the old screen or enclosure. Old silicone holds firmly, so it has to be cut away carefully to avoid scratching the tiles, the floor or the edge of the shower tray. Every trace of the old sealant must come off, because new silicone does not stick to old silicone.

Next comes measuring. The fitter measures the width and height of the opening at several points: top, middle and bottom. A spirit level or a laser shows whether the walls are plumb, whether the corner is truly square and whether the tray or the bath rim is level. In older houses and flats that is rarely the case. Measuring always happens after the tiling is finished, never before.

With made-to-measure screens there is a very good reason for this care: toughened glass cannot be cut or drilled once it has been toughened. All holes for hinges and brackets are made at the glass works beforehand. A measuring mistake means a new panel.

The fitting itself has these stages:

• Marking out the positions of the wall profiles, hinges and brackets
• Drilling through the tiles with a diamond or tile drill bit at low speed and without hammer action
• Choosing wall plugs to suit the wall and fixing the wall profiles or brackets
• Lifting the glass in with suction lifters and setting it plumb and level
• Fitting the hinges, seal strips and magnetic profiles
• Sealing the joints with the wall and the tray, bath or floor using sanitary silicone sealant

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

Most screens are fitted onto a shower tray. The glass or its bottom profile stands on the edge of the tray, so the tray has to be bedded firmly and set level. If it flexes or rocks under weight, the silicone joint between glass and tray will crack sooner or later and water starts to get underneath.

For a corner enclosure, one or two fixed panels are fitted with a door between or beside them. In an alcove between two walls, a single panel with a door is often enough. Choose the door type to suit the room:

• A hinged or pivot door needs clear space in front of the shower, and it must not hit the basin or the radiator
• A sliding door saves space, but its track and rollers need cleaning and adjusting from time to time
• A bifold door suits narrow bathrooms, although it has more joints and seals

A bath screen replaces the shower curtain. It can be a single fixed panel, a hinged panel that swings in and out, or a folding screen made of two to five sections. It is fixed to the wall above the bath rim, and the bottom edge of the glass finishes just above the rim.

Points to watch:

• The bath rim must be straight, and the bath must sit on a solid base or on feet that do not move
• With a hinged screen, check that the glass does not catch on the mixer, a shelf or a towel hook as it opens
• A bath with a curved rim or a corner bath needs a screen made specifically for that shape
• The seal along the bottom edge of the glass must reach the bath rim, otherwise water splashes out every time someone showers

Fitting a bath screen is usually simpler than fitting a full shower enclosure, because there is only one panel and one wall profile. The fixing still has to be just as solid, because a hinged panel acts like a lever on the hinges and the wall.

A framed screen has the glass held in an aluminium or stainless steel frame. The frame offers some adjustment, so it can cope with a slightly uneven wall. It suits most ordinary bathrooms and is easier to fit. The downside is that dirt and limescale collect in the profiles.

A frameless screen is just glass with a minimum of fittings. It looks light and makes a small bathroom feel bigger. It is easy to clean, but it needs straight walls, precise measuring and a solid wall behind the tiles, because thicker glass is heavy.

A made-to-measure screen makes sense in a loft bathroom with a sloping ceiling, in an irregular alcove or anywhere a standard size does not fit. It is produced from the site survey, so the wait is longer.

Shower screens use toughened safety glass, usually 6 to 10 mm thick. If it breaks, it shatters into small blunt pieces rather than sharp shards. The look is a matter of choice:

• Clear glass lets the light through and suits small bathrooms
• Frosted or satin glass gives more privacy
• Sandblasted or patterned glass works as a design feature
• Glass with a water-repellent coating lets water run off more easily and holds less limescale

A shower without a tray, where the glass stands in a U channel set into the floor, is a walk-in shower. That is a separate job with different demands on the floor and the fixings. This article covers screens on shower trays and on baths.

The simplest case is one fixed panel with no moving parts. A hinged door needs precisely set hinges, otherwise it starts to swing open by itself or closes at an angle. A sliding door has a more complicated mechanism and takes longer to adjust.

These things add the most time and effort:

• Removing the old screen and cleaning off old sealant
• Walls out of plumb, corners that are not square, or a tray or bath that is not level
• Large-format or very hard tiles that are difficult to drill
• A weak wall, for example plasterboard without a timber or board pattress where the brackets go
• A badly placed shower valve or waste that has to be moved first
• Heavy glass panels that need two people to lift
• Several panels in one enclosure, each of which has to be aligned and sealed separately

If the pipework or the waste needs changing, that is a job for a plumber before the tiling starts. The screen goes in right at the end, once all other work is finished.

Poor sealing. Cheap silicone without a fungicide soon turns black, and silicone applied to a damp or greasy surface peels away. Water then runs under the floor tiles, into the wall or under the bath. Silicone goes only onto a clean, dry surface and must be left to cure properly.

Drilling through the tanking. Behind the tiles in a shower there is usually a waterproofing membrane or tanking layer. Every hole breaks it, so the plug holes are filled with silicone before the plugs go in. In practice it often turns out that a leak comes from these unsealed holes rather than from the screen itself.

Fixing only into the tiles. A bracket has to reach solid masonry or a reinforced backing. Otherwise the screen works loose over time and the door starts to stick.

Measuring before tiling. Adhesive and tiles change the size of the opening by several millimetres. With made-to-measure glass that is enough for it not to fit.

Seals fitted the wrong way round. The bottom seal with a flap must point into the shower or the bath. Turned the other way, it leads water out.

A rocking tray or bath. If the base under the glass moves, no silicone will last long. The tray or bath has to be packed and bedded firmly before the screen goes on.

A practical homeowner with a helper and the right tools can manage a framed shower enclosure or a simple bath screen from a kit. Leave frameless screens with heavy glass and made-to-measure panels to a professional. Always follow the manufacturer's fitting instructions.

1. Check that every part is in the box and that the glass is undamaged, especially along the edges.
2. Remove any old silicone and degrease the surface.
3. Use a spirit level to check that the tray or bath rim is level and does not move.
4. Hold the wall profile in place, set it plumb with the spirit level and mark the holes.
5. Put masking tape over the drilling points and drill with a tile bit, hammer action off.
6. Fill the holes with silicone, push in the wall plugs and screw the profiles to the wall.
7. With your helper, lift the glass into the profiles and never rest a glass edge on the floor tiles or the bath.
8. Adjust the door or hinged panel so that it moves freely and sits flush.
9. Fit the seals and run silicone along the outside of the joints with the wall and the tray or bath.
10. Leave the silicone to cure for the time the manufacturer gives, then test the shower.

At handover, look over the finished screen carefully and try it out. Check that:

• The glass has no scratches or chipped edges
• The screen stands plumb and does not move when pressed gently
• The door or hinged panel moves smoothly, does not swing open on its own and closes properly
• The silicone joints are continuous, smooth and free of gaps
• The seals face the right way and run the full length
• Once the silicone has cured, no water escapes during a test shower
• You have received the care instructions and the warranty terms

A simple habit makes the screen last longer: after each shower, wipe the glass with a squeegee and air the bathroom. Clean with mild products without abrasives or strong acids, which damage the water-repellent coating and the fittings. Check the seals now and then and tighten any loose screws.