How to Install a Bathroom Sink & Taps

Fitting a new bathroom basin is a brilliant way to refresh your space. It might seem like a big job, but with the right tools and a bit of patience, a successful sink installation is a completely achievable DIY project.

This guide will show you exactly how to fit a bathroom basin with a ceramic pedestal. We'll also talk you through installing basin taps, fitting the basin waste, and securing the trap.

Start by watching the quick how-to video included on this page for a visual overview of the project from start to finish. Once you've watched the video, you can follow our detailed step-by-step instructions below to guide you through the work.

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Tools

Materials

Safety

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Turn off your mains water supply, drain the pipes, and carefully cut away the old sealant to detach and remove your old bathroom sink.
Use a pipe and cable detector on your walls, mark your fixing points accurately, and secure the new pedestal and basin using the correct wall plugs or support boards.
Wrap PTFE tape around the tap threads, secure your new taps with a basin wrench, and apply a neat bead of silicone sealant around the edges to make everything watertight.

Planning your bathroom basin installation

Before you pick up your tools, it's important to do a little bit of planning. Installing a pedestal basin is a relatively straightforward task, provided your existing plumbing doesn't need to be adjusted too much.

However, if the position of your new bathroom basin means that your pipework needs to be rerouted, it's always best to contact a qualified plumber to handle that part for you. If you're simply replacing an existing basin in the exact same spot, then consider replacing the visible plumbing at the same time. Upgrading your pipes gives a much cleaner finish, especially as the pipework behind a pedestal basin tends to be visible.

Here are some other things to consider:

Different bathroom sinks have different fitting requirements. Because of this, you should always check the manufacturer’s instructions before you start your bathroom basin installation. Carefully unpack your new basin and check that you have all the necessary parts and fittings before you remove your old sink.
You'll also need to check your wall type. The fixings you need will depend entirely on the wall you're attaching the basin to. Keep in mind that the fixings provided in the box tend to only be suitable for solid masonry walls. If you're fitting your new basin to a plasterboard or stud wall, you'll need to pick up specialist plasterboard fixings.
While the pedestal takes most of the weight of the basin, you might need to install a wooden support board behind the wall if you can’t fix your screws directly into a timber stud.

Staying safe while you work

Safety always comes first when you're taking on a DIY plumbing project.

Always turn off the water supply at the mains stopcock before carrying out any plumbing work.

When you're removing an old basin, wear rubber gloves and safety goggles to protect yourself from old sealant, debris, and any trapped dirty water. You should also keep your safety goggles on whenever you're using a drill.

Most importantly, use a reliable cable and pipe detector to check the exact areas where you plan to drill. This helps you avoid hidden water pipes and electrical cables behind the plaster.

How to install a bathroom sink

Before you can start installing, you need to know how to remove a sink safely. Start by turning off the water supply using your main stopcock. Next, open up your bathroom sink taps to drain any remaining water sitting in the pipes.

Once the pipes are completely empty, you can disconnect the hot and cold water supply and the waste pipes. Take care to loosen the nuts slowly before fully detaching them. It's a good idea to place an old towel or a small bucket underneath the pipes to catch any water left inside the basin trap during this process.

Take your utility knife and carefully cut through any old silicone sealant around the edges of the sink. Gently lift the old basin away from the wall and set it aside.

Begin by making sure your working area is totally clean. Scrape away any leftover pieces of old sealant and sweep up any debris.

Place your new pedestal in its final position and sit the ceramic basin on top. Make sure that the back of the basin sits perfectly flush against the wall. Grab your spirit level and place it across the basin to check that both the pedestal and the basin are perfectly level.

Once everything is sitting straight, take your pencil and mark the fixing points for both the basin and the pedestal on the wall and the floor. Carefully move the basin and pedestal out of the way and place them somewhere safe.

Take your pipe, cable, and stud detector and scan the wall to make sure there are no hidden hazards where you plan to drill your holes. If you're fixing the sink to a stud wall, use the detector to find the wooden studs. If your studs don’t line up with your pencil marks, you might need to install a timber support board to hold the weight.

Place the pedestal back into position and sit the basin on top once more. Double-check that everything is still level.

Use a suitable drill bit for your specific wall type to create pilot holes at the fixing points you marked earlier. If you're drilling into bathroom tiles, stick a piece of insulating foil tape or masking tape over the mark before you drill. This creates a bit of friction and stops the drill bit from slipping and scratching your beautiful tiles.

After drilling, insert the correct fixings into the holes. Use sturdy wall plugs for masonry walls, or specialist plasterboard fixings for stud walls.

Now it's time to secure the basin to the wall and the pedestal to the floor. Here is how to handle different surfaces:

Masonry walls: Make sure the fixing bolts pass smoothly through the holes in the back of the basin. Tighten the washers and nuts onto the bolts.
Stud or plasterboard walls: Insert and secure a screw on either side of the basin directly into a wooden stud.
Concrete or tile floors: Drill two 8mm holes approximately 40mm deep into the floor. Insert your wall plugs until they sit flush with the floor surface. Secure the pedestal with two 50mm screws driven into your pre-drilled holes.
Wooden floors: Drill two 4mm holes around 30mm deep. Secure the pedestal using 50mm screws.

Take great care not to overtighten any of these fixings. Too much pressure can easily crack and damage the ceramic. It’s best to hand-tighten them or use a handheld manual screwdriver rather than a power drill.

How to install bathroom taps

If you're replacing bathroom taps or fitting brand new ones, the process is very similar.

Place your new bathroom taps into the pre-drilled holes on the top of the basin. Secure them from underneath using a basin wrench to tighten the nuts.

Wrap a few layers of PTFE tape (plumber's tape) around the threads of the water supply connectors. This helps create a completely watertight seal.

Attach the flexible tap connectors to your hot and cold water supply pipes. Tighten these by hand first to make sure the threads cross properly, before securing them firmly with an adjustable wrench.

How to install a sink waste and trap

Next, you need to install the basin waste.

Apply a very small amount of silicone sealant around the rubber washer to guarantee a watertight connection.

Tighten the nut underneath with your adjustable wrench, remembering not to overtighten it.

Fit the waste trap beneath the basin, checking that all the internal washers are properly seated in place. Secure the washer by tightening the nut with an adjustable wrench or self-grip pliers.

Finally, place the waste outlet pipe into the trap. Hand-tighten the fittings first and then securing them with a wrench.

Finishing touches

Once all your plumbing is connected, slowly turn your mains water supply back on. Open your bathroom sink taps and watch the water flow.

Carefully check for any drips or leaks around the tap connections, the waste trap, and the supply pipes. If you spot any water escaping, simply turn the taps off and gently tighten the loose fittings or connections until the seals are perfectly watertight.

The final step is to waterproof your work. Load your cartridge gun with silicone sealant and apply a neat, continuous bead where the back of the basin meets the wall.

You'll also need to run a bead of silicone along the base of the pedestal where it touches the bathroom floor. This creates a flexible, waterproof seal that stops water from seeping into any gaps behind the sink.

Allow the sealant to dry fully according to the manufacturer's instructions before you start using your new sink.

Caring for your new sink and taps

To keep your new basin looking fresh, always use gentle cleaning supplies that are appropriate for ceramic surfaces. Avoid harsh, abrasive chemicals that can scratch the glaze or damage the shiny finish on your new bathroom taps.

Fitting a new bathroom sink and taps is a highly manageable DIY task that can make a massive difference to your bathroom’s look and overall functionality. With the right tools, careful preparation, and a little patience, a successful sink installation is something you can complete confidently.

We know that taking on plumbing work can feel a bit daunting at first. But by breaking it down into these straightforward steps, you'll be able to tackle your bathroom basin installation smoothly. If this has got you in the mood for some more bathroom DIY, take a look at our guide on how to fit a toilet.

FAQs

Using plumber’s tape (PTFE tape) on all your threaded pipe connections is a great way to prevent annoying leaks. You should tighten all your fittings securely, but avoid overtightening them, as this can easily damage the threads and cause drips. Always test your water connections before sealing up the edges of the sink.

Yes, you definitely do. Silicone sealant needs to be applied around the back edge of the sink where it meets the wall or countertop, and around the base of the pedestal. This stops water from seeping down the back of the basin and causing damp or structural damage to your walls.

If you are fixing your pedestal basin onto a plasterboard or stud wall and you can’t fix your screws directly into a wooden stud, you will need to install a timber support board behind the plasterboard. This gives the heavy ceramic basin a solid anchor point. You'll also need to use specialist plasterboard fixings rather than standard masonry wall plugs to ensure everything stays secure.