When you're choosing a shower, it's important to pick one that's compatible with your home's plumbing system, and they're put together in different ways too. Use our guide to help fit your new shower.
Tools & materials required
Choosing a shower - which water system do you have?
If you have a gravity-fed system (with a hot water cylinder and a cold water storage cistern in your loft), you have the most options. You could go for a mixer shower with or without a pump, a power shower or an electric shower.
If you've got a combination boiler or your cold water comes directly off the mains, your options are a mixer shower or an electric shower, as a combi boiler or mains supply does not allow you to fix a pump.
How to fit an electric shower
An electric shower has an element like a kettle that heats the water as it passes through. You control the temperature by changing the rate at which the water passes over the element. Most showers don't have a thermostat - so if the temperature of the incoming water varies, so will the temperatures of your shower.
You can install an electric shower over your bath or in a separate cubicle. When you're deciding where to put it, make sure you leave enough room around it to remove the front cover, as it might need servicing in the future. Depending on the type of unit, the water supply pipe could enter from the top, bottom or rear. So take a look at the manufacturer's instructions and make sure you have the right amount of cable emerging from the wall to connect to the terminal block.
Before connecting your unit, turn on the water to flush any debris from the water inlet pipe, as any small particles could damage your new shower. Then turn the water off and drain the pipe.
Before you fit your shower, you'll need to prepare the pipework and install an electricity supply.
Preparing the pipework
Start by running a single 15mm pipe from the cold water supply near the storage tank to the wall where you're putting the shower. Holding the shower unit in place, mark the position for the inlet pipe and power supply cable. Make sure you use a pipe and cable detector to check there are no hidden pipes or cables before you drill into the wall. Then run the pipe through the wall at the place you've marked. Fit an isolating valve in the pipe, and insert the correct connector for the unit.
Providing the power supply
Drill a hole in the wall for the electric cable. The size of cable you need depends on the length of the run and the kilowatt rating of the shower unit, so make sure you check the manufacturer's instructions. Run cable from the shower unit position to a ceiling-mounted double-pole pull-cord switch. This should have an on/off indicator, and you mustn't put it in Hazard Zones 1 or 2 as defined by the IEE Wiring Regulations. An electric shower needs its own dedicated circuit from the consumer unit, and for safety you must get an electrician to make the final connection for you. The circuit must also be protected by an RCD (residual current device).
Hold the shower unit in position and mark the fixing holes with a chinagraph pencil. Drill holes at the marked positions with a masonry bit. If you're drilling into a tiled surface, it's a good idea to use a tile bit or stick masking tape on the tiles to stop your bit slipping. Fit some wall plugs, and squeeze a little sanitary silicone sealant onto each one.
Feed the pipe and electric cable through the backplate of the unit. Then screw it to the wall using the screws supplied.
Connect the inlet pipe to your shower unit, using a pipe wrench to tighten the compression fitting.
Fix the cable to the unit by connecting its live and neutral cores to the terminals marked 'load,' and its earth core to the earth terminal.
Fit the cover according to the manufacturer's instructions, ensuring that the rubber seal is in place.
Fit your rail, making sure you put it high enough so your shower head doesn't dangle less than 25mm from the spill-over level of your bath, shower tray, wash basin or bidet. Otherwise, dirty water might siphon back into your clean water supply.
Screw one end of the hose to the handset, making sure you include any washers supplied. Follow the manufacturer's instructions to check everything is working correctly before finally screwing the other end to your shower unit.
How to fit a thermostatic mixer shower
Whether your thermostatic mixer shower has got a pump or not, you can supply it via branch pipes from your hot and cold plumbing system. Try to join them as near as possible to your cold and hot water tanks, and run them to the shower position and through the wall.
The hot and cold water pressure in a gravity-fed system is determined by the height of the cold water tank above your shower.
Without a pump, you need at least one metre between the bottom of your tank and the shower head to give you a decent flow rate and pressure. If you don't have enough difference in height, you'll either need to raise your cold water tank or fit a pump in your system.
1. Ensure your mixer is installed, commissioned, operated and maintained in accordance with the manufacturer’s recommendations.
2. Read the manufacturer's instructions carefully.
3. The shower unit must not be fitted where it may be exposed to freezing conditions.
Check the contents to make sure all parts are present. Before starting the mixer installation, make sure all the openings on the valve are carefully covered to prevent any debris getting in while working on the supply pipework.
Be sure of the type of wall you have and whether the shower valve is suitable.
When you have decided on the position of the shower and direction of pipe entry (for example rising, falling or rear entry), complete the pipework to the shower area. The hot and cold water pipes should be securely attached within the wall or panel to support the valve and prevent movement after installation.
Caution! Make sure that the compression olives are fitted and all pipework is flushed through before connecting to the shower valve.
Turn on the water to check for leaks.
Install the outlet fittings (refer to your manufacturer's installation guide for specific instructions).
Adding a pump
Adding a booster pump to your thermostatic mixer shower can more than double the flow rate. You can hide the pump under a bath or tuck it away in an airing cupboard or loft, so you won't see (although you might hear it in action). But remember that you can't connect a pump to a combi boiler or a cold water supply coming straight off the mains. And to get the most out of it, you might have to install a bigger hot water cylinder.
How to fit a shower mixer valve and rail
Try and set your rail high enough for the tallest person in your house - but not so low that your shower head dangles any less than 25mm from the spill-over level of the shower tray, bath or nearby basin. If it's too low, used water might go back into your household supply.
Start by sealing the hole around each inlet pipe with some sanitary silicone sealant. Turn on the hot and cold taps to flush out the pipework. Then, before you attach your pipe trims, fix a coupler onto each pipe and fit the thermostatic mixer valve using an adjustable spanner. Turn on the hot and cold water to check for any leaks. If everything is watertight you can remove the mixer, fit the chrome pipe trims and re-fit the mixer valve.
Fit the lever and holder to the slider rail. Then put the brackets on the ends of the rail and mark the position of the fixing hole for the lowest bracket.
First, use an electronic detector to check carefully that there are no hidden pipes or cables. Then drill where you've marked the position of the lower bracket. Pop in a wall plug and squeeze a spot of sanitary silicone sealant onto it.
Remove the slider rail from the brackets and fix the bottom bracket to the bottom hole, using the screw supplied. To find the position of the top fixing hole, just put the rail back onto the bottom bracket and put the other mounting bracket on the top of the rail. Use a spirit level to check it's vertical, and mark the top fixing hole on the wall.
Take the rail off, and drill and plug the wall as you did before. Then screw the top bracket in with the rail in place. Finally, fit bracket covers onto the top and bottom brackets.
How to fit a shower tray
When the waste pipework is ready, you can fit your shower tray and connect its waste outlet to the trap. But make sure you read the manufacturer's installation instructions, as different designs might need to be installed in slightly different ways.
Hold the tray on its side and run a bead of sanitary silicone sealant around the waste hole.
Put the waste outlet into the hole so it goes into the sealant. Make sure you've fitted any washers that were supplied, and use an adjustable spanner to screw on the locking nut. Then you can fit the trap to the waste outlet.
Put on some protective gloves and mix the mortar. Take a trowel to put a thin layer on the floor where your tray will go, then put it in place.
Bed the tray down into the mortar, using a spirit level to check it isn't sloping. If you can't get it exactly level, you might need to lift up the tray and adjust the mortar. Tidy the edges and remove any excess mortar with the trowel. Then finish the job by opening the floor hatch and connecting the trap to the waste pipe.
How to fit a shower enclosure
You can buy a shower enclosure as part of a new bathroom or add one to your existing suite. They can fit either into the corner of a room or against a flat wall. There are a variety of door styles for your enclosure such as hinged or pivoted, and for a great space saving option, there are folding and sliding doors.
Before you fit your enclosure, you'll need to have your shower tray, mixer valve, pipework and tiling in place. The example below shows a corner enclosure with curved sliding doors - but there are lots of designs available and each is installed in a slightly different way, so make sure you read the manufacturer's instructions. With any enclosure, it's essential that the wall and tray are fully waterproof and the uprights of the frame are vertical.
Top tip - Extractor fans
Showers generate a lot of steam and condensation, which can lead to problems with damp. So it's well worth thinking about installing an extractor fan to ventilate your room.
The waste pipes and trap
Before choosing your shower enclosure, you'll need to work out how you're going to run the drainage pipes, and check how much height you need under the tray for the pipework. You might be able to cut a hole in the floor to fit the waste pipe. If so, you'll also need to make an access hatch. To do this, you can either extend the hole for the waste trap beyond where the outside edge of the shower tray will be, or make a separate hatch nearby within reach of the trap. If your floor is solid, or you can't get enough of a fall for drainage under a suspended floor, you have a couple of options. You could go for an enclosure with a step up to the tray, or raise your tray above floor level by fitting it on a plinth. If you don't have enough space under the shower tray to fit a shallow P-trap, you could fit a compact trap. This is specially designed to give you the necessary water seal, while being shallow enough to fit under most modern shower trays. Its removable grid also makes it easy to clean.
Lay the two fixed side panels flat, and put some generous beads of sanitary silicone sealant into the curved channels at the top and bottom. Then attach the head and sill rails with the screws provided - taking care not to over-tighten them.
Slide the plastic guide tracks into the head and sill rails.
Use a junior hacksaw to shorten the plastic guide tracks if they're too long.
Push two door stops into the guide track in the head and sill rails. You can move them into the middle, but don't fix them yet.
Stand the shower enclosure upright and slide the curved sliding doors into the head and sill rails, making sure that the doors are the right way around. Then put another doorstop into both the head and sill rails.
Attach the wall channels to each side of the enclosure, and stand it on the tray - checking it's vertical with a spirit level. Then, from the inside of the enclosure, use a chinagraph pencil to mark the position for the fixing holes through the pre-drilled holes in the wall channels.
Take off the enclosure, and check for hidden pipes and cables behind the fixing positions with an electronic detector. If all is clear, drill fixing holes in the marked positions. Push wall-plugs into the holes, making sure they go in beyond the depth of the tile.
Run an unbroken bead of sanitary silicone sealant down both wall channels. Then put the enclosure onto the base and screw in the fixing screws. Wipe off any excess sealant and check the instructions to make any final adjustments to the sliding doors.
From the inside, drill through the holes in the wall channels and into the frame. Put in the screws provided and cover the heads with screw caps. Drill through the plastic track and inner head channel, and then screw the doorstops into place.
Seal the join between the tray and the tiled wall with a continuous bead of sanitary silicone sealant. Do the same around the outside edges of the enclosure.
For your safety, these products must be installed in accordance with local Building Regulations. If in any doubt, or where required by the law, consult a competent person who is registered with an electrical certification scheme. Further information is available online or from your local authority.
All new and modified installations must comply with the latest IEE Wiring Regulations. Either use an electrician registered with the self certification scheme prescribed in the regulations, or if you carry out the work yourself, you must notify your Local Authority Buidling Control Department to get your work inspected and tested.