Shower Installation

In picking out a shower, your client has a lot more to consider than just the way it looks. When you’re plumbing a new bathroom it’s important to take your client’s existing plumbing system into account and select a type of shower that will work with it. That said, no matter what type of plumbing system they have, you’ll have a few different options.

For gravity-fed systems

In gravity-fed plumbing systems, the water from the shower comes from a cold water cistern and a hot water cylinder stored in the loft. This kind of system allows for the widest choice of shower types. You could opt for a power shower, an electric shower, or a mixer shower with a pump or without.

For combination boilers or systems where cold water comes from the mains

Combi boilers give high pressure water and so a water pump is generally not required. Electric showers are not usually compatible and so suitable shower types are thermostatic or manual mixer units.

Read on for overviews of how to install two shower types commonly found in modern bathroom designs.

The steps below offer a simple and general guide that may be familiar to you. They don’t replace the more important regulations and manufacturer’s advice for your specific model.

If you’re looking for additional tips, watch this video on installing an electric shower by Triton Showers.

The water should be switched off for most of the installation process, though you should switch it on briefly at the start to clear the inlet pipe.

Step 1: Choose your spot

You’ll likely have decided where the shower unit will go before you get to the installation stage. However, save yourself future hassle and make sure the location offers easy access for future servicing. Other easy things to forget include the angle the water supply pipe will meet the unit from, and whether the power cable you’ve already installed can easily reach the unit.

Step 2: Make space for the pipe

Put down a 15mm pipe that will run from the cold water supply to the wall the shower will be mounted on. Mark where you’ll need to drill into the wall for the inlet pipe and power supply cable. You probably don’t need a reminder but check the wall for hidden pipes or cables using a pipe and cable detector before you start drilling. After running the pipe through the wall, fit an isolating valve and insert the connector.

Step 3: Lay the cable and install the switch

Double-check you have the right size of cable for your shower unit and the length of the cable run. If in doubt, the instructions accompanying the shower unit should have advice on this.

When you install the power cable, make sure you comply with wiring regulations. The shower must have its own circuit, which has to be protected by an RCD (residual current device). The power should be operated by a ceiling-mounted double-pole pull-cord switch, which must clearly show when it is on or off. Don’t install the pull-cord in the areas referred to by the IET Wiring Regulations as Hazard Zones 1 or 2.

Step 4: Affix the shower unit and connect it up

Mark and drill fixing holes for the shower using a masonry bit, or a tile bit if you’re drilling through bathroom tiles. Lead the pipe and cable into the shower unit’s backplate, then screw it to the wall.

Next, connect the inlet pipe properly, using a pipe wrench. Connect the live and neutral cores of your power cable to the terminals inside the unit that are marked “load”. Connect the earth core to the earth terminal.

Step 5: Attach the rail and handset

Fit the rail that will support the handset to the wall, according to the height requirements of your client. Screw the shower handset to the hose and screw the other end into the shower unit.

This is pretty much the same as installing an electric shower, so won’t phase you. As before, consult the specific regulations and manufacturer’s advice. You’ll also need to clear the inlet pipe and make sure the water is switched off during installation.

The most important differences, apart from the electrics, relate to the pump.

Deciding if you need a pump

Of course, if you are connecting to a combi boiler or pressurised cylinder a pump is not required. To achieve a good level of water pressure, you’ll need a minimum of one metre between the shower head and the bottom of your water tank, usually stored in the loft overhead. If you don’t have this much space and elevating the water tank isn’t an option, you’ll need to fit a pump.

Fitting a pump

Even if you don’t technically need a pump, fitting one can have an enormously positive impact on the water flow rate. Install the pump somewhere it won’t be seen, like under the bathtub or in a cupboard. Keep in mind, that you might need to install a larger hot water cylinder to get the best results out of the pump.

If your shower isn’t positioned over a bathtub, you’ll obviously need to fit a separate shower tray and enclosure, which is necessary for most small bathroom designs.

You’ll need to consider the shape of the shower tray, so it fits the available bathroom space. Keep in mind how the doors open and the position of other bathroom fittings – most shapes can be used with a variety of enclosures.

Square shower trays are a popular option for small bathrooms, as they come in various sizes and materials. For a spacious shower design, a rectangular shape offers a more comfortable space and is a great choice if you need to replace an existing bath. A quadrant shower tray with a curved front is another practical shape for a smaller bathroom, as it is specifically designed for a corner space. There are also more unusual shapes, including D or P shaped trays.

Walk in shower trays are lower in height than standard trays for easier access into the shower. If plumbing below a slim line tray is problematic, then a riser kit can be used to give space for the shower trap and waste pipe to be fitted.

Even in the case of bathroom suites that include a bathtub, if there is space some clients prefer having a separate shower enclosure.

When choosing the shower enclosure, you’ll want to bear in mind the size of the bathroom and shape of the shower tray. To guarantee a good fit, we suggest sourcing both enclosure and tray together.

Bifold doors and sliding doors are recommended for small bathrooms, as they help to save space. For a shower basin with a curved front, popular options include, sliding or hinged doors. If you are fitting a walk in shower tray, make sure the enclosure’s dimensions are compatible.

Before starting the installation, have the shower tray, bathroom tiles and pipework in place.

Assemble the doors and side panels before you attach the enclosure. Once this is done, place the enclosure upright in the shower tray so you can mark the points where you’ll need to drill the fixing holes. As always before drilling, use a detector to check for cables and pipes hidden in the wall.

When you’ve fitted the enclosure, seal off all the joins with sanitary silicone sealant.

If you’re relatively new to installing enclosures, for more advice watch this DIY doctor’s video on shower enclosure installation.