How to Fit a Basin Tap — Complete UK DIY Guide
Modern monobloc basin taps come with flexible tails, making DIY replacement a 45-minute job. Here is the trade method.
Step-by-step method
1. Isolate water and drain
Close isolating valves on hot and cold feeds under the basin. Open the tap to drain residual pressure.
2. Remove the old tap
Unscrew flexi tails from isolators. Undo the back nut under the basin (may need a tap wrench in tight spaces). Lift out old tap.
3. Fit the new tap
Add rubber seal to underside. Feed tails through hole. Fit horseshoe washer + back nut from below, tighten square.
4. Connect flexi tails
Hot to red, cold to blue isolator. Hand tight + quarter turn with spanner. Do not overtighten — the rubber seals do the work.
5. Open water and check
Open isolators slowly, run tap for 60 seconds, feel joints for leaks. Reseal around the tap base with clear silicone.
Frequently asked questions
Do I need plumbers putty or silicone under a basin tap?+
Most modern taps use a rubber seal — no putty needed. If your basin surface is uneven, add clear silicone as backup.
What size are basin tap flexi tails?+
UK standard is 15mm compression at the isolator end, 1/2" BSP at the tap end. Length usually 300mm.