Replace a basin and pedestal — HomeGraft

Remove your old basin and pedestal, then fit and plumb in the new one safely, checking for leaks.

RB-01Turn off the water and clear the areaTurn off the isolating valves under the basin, or the stopcock (usually under the kitchen sink) if there are none. Check the stopcock actually turns before you start, so you know it works if you need it in a hurry. Open the taps to drain the pipework, and put a bucket under the trap to catch any leftover water. Lay dust sheets down to protect the floor and bath.

1 each · Dust sheet

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1 each · Bucket

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RB-02Disconnect the old basinUndo the flexible tap connectors or compression joints under the basin with an adjustable spanner. Unscrew the waste trap from the tailpiece and let any water drain into the bucket. Support the basin with one hand as you undo the last fitting - it's heavier than it looks once it's loose.

1 each · Adjustable spanner

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RB-03Lift off the old basin and pedestalLift the basin off its wall bracket and clear of the pedestal, then set it down on an old towel. Unscrew the pedestal from the floor if it's fixed down, and remove it. Check the wall behind for damage, old sealant or leftover fixings you'll need to deal with later.

RB-04Fit taps and waste to the new basin before hanging itIt's much easier to fit the waste kit and reconnect your taps while the basin is upside down on a padded bench. Fit the waste kit with a thin bead of silicone or plumber's putty under the flange, then tighten the back nut underneath by hand plus a quarter turn with pliers. Refit your existing taps with new washers if the old ones are worn, without overtightening the back nuts.

1 each · Basin waste kit (click-clack)

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1 tube · Plumber's putty

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1 roll · PTFE tape

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RB-05Work out what's behind the wall before you drillTap along the wall where the bracket will go - a dull, solid sound means brick or block, a hollow sound means plasterboard on a stud frame. Run a magnet or stud detector along the wall to find the line of screw heads that marks each stud, then drill a small pilot hole: pale wood dust means a timber stud, fine grey metal swarf means a metal stud. Cables and pipes can run almost anywhere in a wall, not just in the usual safe zones, so always use a cable and pipe detector - but still treat the wall as if something is there, because detectors miss cables that are deep, in metal conduit, behind metal-backed plasterboard, and a metal stud frame can confuse a cheap detector completely. You checked your stopcock works in step 1, so you're ready to shut the water off fast if you hit a pipe; if you have any doubt at all, isolate the electrics at the consumer unit before you drill.

1 each · Cable and pipe detector

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RB-06Mark and drill the wall bracket fixing holes for your wall typeThe right fixing depends on what you found in the last step. Solid brick or block: drill 8mm holes 50mm deep with a masonry bit, fit a red plastic wall plug, and use a 50mm No.8 or No.10 screw. Plasterboard on timber studs: drill a small pilot hole into the centre of the stud and use a 50mm wood screw straight into the timber - no plug needed. Plasterboard on metal studs: metal studs won't hold heavy weight or anything that pulls away from the wall, like the lean a basin takes when someone uses it, so never use a wood screw or plastic plug - they strip straight through 0.5mm steel. Use a self-drilling metal-stud fixing or a toggle-type hollow-wall anchor, and fit a timber noggin between the studs if you can for a properly secure basin. Dot-and-dab plasterboard: the board is stuck to the masonry behind with adhesive dabs and there are air gaps between them, so use a long fixing - at least 75-100mm - that reaches through the board into solid masonry, with a matching plug. Lath and plaster: this old thin timber-and-lime wall is brittle and cracks easily, so drill slowly, aim for a timber batten behind if your detector finds one, and otherwise use a heavy-duty hollow-wall anchor spread across the laths.

1 each · Masonry drill bit 8mm

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4 each · Red plastic wall plugs

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4 each · Wood screws 50mm No.10

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4 each · Metal stud self-drilling fixings

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4 each · Toggle-type hollow-wall anchors

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4 each · Long masonry fixings 100mm (dot-and-dab)

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RB-07Fix the wall bracket in placeScrew the wall-fixing bracket to the wall using the fixings you've chosen, checking it's level with a spirit level before fully tightening. Give the bracket a firm tug once fixed to make sure it doesn't move.

1 each · Spirit level

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RB-08Position the pedestal and offer up the basinStand the pedestal roughly in place, slightly forward of the wall so you can slot the basin's back edge onto the bracket. Lower the basin onto the bracket and let its rear edge rest on the pedestal. Check the basin sits level side to side, packing under the pedestal base with thin card if it rocks.

2 each · Card packers

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RB-09Mark and drill the pedestal floor fixingWith the basin resting in place, mark the pedestal's screw holes through its fixing lugs onto the floor. Lift the basin clear, then drill pilot holes at the marks - a 4mm pilot bit for a timber floor, or a masonry bit and plug for solid concrete or tiled floors. Pipes can run under bathroom floors too, so check for signs of existing pipework and only drill as deep as the screw needs.

1 each · Pilot drill bit 4mm

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2 each · Floor plugs (for tiled/concrete floor)

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RB-10Fix the pedestal and re-seat the basinScrew the pedestal to the floor through its fixing lugs, tightening gently - pedestals can crack if overtightened. Lower the basin back onto the pedestal and wall bracket, then secure it with the basin's retaining screws or clips.

2 each · Pedestal fixing screws

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RB-11Reconnect the water supply and wasteConnect the tap tails to the isolating valves or supply pipes with flexible tap connectors, hand-tight plus a quarter turn with a spanner - don't overtighten flexible hoses or they can split. Reconnect the waste trap to the tailpiece, checking the washers are seated correctly before you tighten the nut.

2 each · Flexible tap connectors 300mm

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1 each · Trap washer

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RB-12Turn the water back on and check for leaksTurn the isolating valves or stopcock back on slowly. Fill the basin and check every joint - tap tails, waste trap, overflow - for drips. Let it drain fully and check the trap again a few minutes later, once water has been running through it.

RB-13Seal the basin to the wallRun a thin, even bead of silicone sealant along the gap between the basin and the wall, then smooth it with a wet finger or a sealant tool. Leave it uncured for 24 hours before splashing water on it.

1 tube · Silicone sealant

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1 each · Sealant gun

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1 roll · Masking tape

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RB-14Tidy up and dispose of the old basinWipe down the new basin and pedestal, and clear any dust or off-cuts from the floor. Fill and make good any old fixing holes in the wall with filler. Take the old basin and pedestal to a household waste recycling centre - ceramic sanitaryware usually isn't taken in normal kerbside bins.

1 tub · Multi-purpose filler

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