Installing a new bathroom sink doesn’t mean that you have to hire a professional plumber to carry out the work, someone who is confident at DIY can easily take on the task. So, check out this step-by-step guide on how to install a bathroom sink.


1. Removing the old sink

Before removing the old sink make sure you turn off the water supply. If you are planning to use your existing basin taps remove them from the sink using adjustable wrenches. Ensure that you don’t remove the earth wire straps from the pipes underneath the basin.

2. Line up the new sink against the wall

Once your old sink has been removed take your new sink and line it up against the wall, make sure you use a spirit level to ensure that the sink is level.

3. Check all the connections

Check that you can connect the water supply pipes and waste directly back to the sink trap and basin taps, if this isn’t possible or you are installing new taps fit flexible tap connector pipes and waste pipe parts so the connections can be made.

The supplied washers and gaskets are used to ensure a watertight seal around the new basin taps. It’s a good idea to fit as many parts as possible to your new sink before installing it, this way you will only have to make one connection underneath the sink once it is in position.

4. Connecting the pipes

Once all the connections have been checked you can connect the waste pipe to the overflow (with the relevant parts), you can then place the basin into a worktop or directly screw it to the wall, make sure to check all the pipes can be connected easily.

5. Sealing the gaps

Finally, use waterproof sealant to seal the gaps and tighten the joints on the flexible tap connectors with the adjustable spanners, ensuring the tap connector pipes aren’t stretched or have any kinks.

Useful advice

basin tap

It’s important that any changes that are made to the plumbing system maintain effective earthing of the metal pipework. An earth wire connects each of these items to a metal earthing block in the consumer unit; this is to prevent electric shocks and any new plastic pipe sections that are added could break this bonding.

If there are isolater valves fitted to the hot and cold water pipes under the sink it means you can switch off the cold water supply to just the sink. Alternatively the cold water can be switched off at the main stopcock. Turn the cold tap on until the water stops running, this will stop the flow of cold water.

To switch off the hot water make sure the boiler and immersion heater are turned off before you drain the hot water. Make sure you turn the valve off, which is on the cold feed pipe to your cylinder and run the hot tap to remove the water in the pipes.

If you are fitting your new sink into a worktop and it’s larger than the the old one you will need to use a jigsaw to make the cut-out bigger. Mark out the area to be cut (with the supplied template) and ensure that the rim of the sink sits on the worktop.