How to fit a bathroom basin

Inspired by the Wickes how-to series. This guide is based on the popular "How To Fit a Basin & Taps" video from the Wickes YouTube channel. It covers the full removal and replacement process in clear steps, and is particularly useful for showing how to fit taps and the waste assembly before the basin goes on the wall — which saves a lot of awkward scrabbling about afterwards.

1. Turn off the water supply and drain the pipes

Turn off the isolation valves on both hot and cold supply pipes under the basin. If there are no isolation valves, turn off at the mains. Run the taps to drain the remaining water in the pipes.

Put a towel and a small bowl under the trap before you loosen anything. There is always residual water in the trap that will spill if you're not ready for it.

2. Disconnect the old basin

Loosen the supply pipe fittings and the trap under the waste. On older basins the trap can be corroded solid — a strap wrench or a firm grip with water-pump pliers usually shifts it. Do not force plastic fittings with metal tools.

Check how the basin is fixed to the wall. Wall-hung basins may have screws or brackets hidden behind the pedestal. With the pedestal removed, the fixings should become obvious.

3. Fit the taps to the new basin before mounting it

Always fit the taps, waste, and any click-clack drain mechanism while the basin is on the floor or a workbench. Trying to tighten tap back-nuts while lying on a bathroom floor with your arm stretched behind a pedestal is deeply unpleasant.

Use a basin spanner for the back-nuts if the gap is tight. Hand-tighten first, then a firm quarter-turn with the spanner is enough — over-tightening can crack the ceramic around the tap holes.

4. Fix the basin to the wall

Mark the fixing positions through the basin bracket holes. Drill into the tiles and wall with a tile bit first, then switch to a masonry bit. Use the right wall plugs for the wall type behind the tiles.

If the basin comes with a pedestal, position the pedestal first and let it support the basin while you mark the fixing holes. The pedestal hides the plumbing but does not carry the weight — the wall brackets do that.

5. Connect the waste and trap

Fit the trap to the waste outlet and position it to align with the waste pipe in the wall. Compression fittings hand-tighten first, then a further half-turn. Plastic traps do not need jointing compound — the rubber seal does the work.

Check the trap has the correct fall toward the waste pipe. A trap that runs slightly uphill will never drain properly and will smell.

6. Connect the supply pipes

Connect the hot and cold flexible tap tails to the supply pipes. Make sure you have not crossed them over — hot on the left, cold on the right as you face the basin is the UK standard. Use PTFE tape on any threaded fittings.

Tighten compression fittings one full turn past hand-tight. Flexible tap connectors are notorious for leaking if under-tightened or over-tightened. Snug is the word.

7. Turn on and check for leaks

Open the isolation valves slowly. Check every joint — supply connections, waste, trap — before you run the taps. Run both hot and cold at full flow for a couple of minutes, then check again underneath.

A dry joint today can start weeping tomorrow once the fitting settles under pressure. Come back and check again after 24 hours. A quick look now saves a bigger problem later.

When to call a handyman

Call Richard if the wall behind the old basin is damaged, if the supply pipes are old copper with corroded fittings, or if the drain position does not align with the new basin's waste outlet. These are the complications that turn a straightforward replacement into a longer job.