Fit a wall-hung vanity unit to a timber stud wall — HomeGraft

Fit a wall-hung vanity unit safely, with the right fixings, noggins if needed, and full plumbing connections in one session.

VU-01Turn off the water and clear the areaFind your stopcock, usually under the kitchen sink, and check it turns fully before you start. Turn it off, then open the bathroom taps to drain the pipes, catching any water left in a bowl or old towel. Clear everything out from under the old basin or vanity space so you have room to work.

VU-02Mark the height and centre lineMost wall-hung vanities sit with the top of the basin 800-850mm above the finished floor, but check your unit's own instructions for the exact figure. Use a spirit level to draw a level line at this height, then mark the centre point where the taps and waste will land. Hold the unit's fixing rail or paper template against the wall to transfer the exact hole positions.

1 each · Pencil

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1 roll · Masking tape

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VU-03Work out what's behind the wallRun a stud detector across the wall at your marked height. A steady line of screw or nail heads under a magnet, plus a dull knock between the marks, tells you it's a timber stud wall; a fine steel swarf from a small pilot hole instead of pale timber dust means metal studs, common in flats and anything built or refitted since the 1990s. If the wall sounds solid all over with no hollow spots, you likely have solid brick or block, or dot-and-dab plasterboard bonded to masonry behind; lath and plaster feels slightly springy with an uneven knock. Cables and pipes can run almost anywhere, so use a detector but still assume something is there - it can miss cables that are deep, in metal conduit, or behind metal-backed board - and isolate the electrics at the consumer unit before drilling if you have any doubt.

1 each · Stud detector or magnet

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VU-04Fit a noggin if you need one (timber stud walls)A wall-hung vanity gets heavy once it's full of water, and it pulls down and away from the wall every time someone leans on it, so it needs solid backing across the studs, not just a fixing into plasterboard. If your studs don't line up with the unit's fixing rail, cut a small inspection hole in the plasterboard, screw a 47x100mm timber noggin horizontally between two studs at the marked height with 90mm timber screws, then patch the plasterboard and let the filler dry fully before hanging anything on it. If the rail already lines up with two studs, or you're fixing into solid masonry or through dot-and-dab to the masonry behind, skip this step.

1 each · Timber noggin 47x100mm, 600mm length

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1 pack · Timber screws 90mm

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1 each · Plasterboard offcut

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1 tub · Filler

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VU-05Fix the mounting rail or brackets to the wallBefore you drill, turn the water off at the stopcock if you haven't already, check again with your detector, then drill a small pilot hole and look at what comes out - pale dust means timber, fine grey swarf means metal. For a timber stud, drill a 3mm pilot hole into the centre of the stud and drive a coach screw or heavy-duty wood screw at least 60mm long. For a metal stud, use a self-drilling metal-stud fixing or a toggle-type hollow-wall anchor rated for the unit's weight - never a plain wall plug or ordinary wood screw, which strips straight through 0.5mm steel. For solid brick or block, drill a 10mm hole 60mm deep, fit a matching plug, and drive a coach screw home; for dot-and-dab, use a fixing 75-90mm long so it passes through the void and at least 40mm into the masonry behind. For lath and plaster, drill a pilot hole through the lath into the stud behind and drive the screw slowly to avoid cracking the old plaster.

4 each · Coach screws 8x60mm

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4 each · Metal-stud toggle fixings

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4 each · Rawlplug and screw, 10x60mm

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4 each · Long frame fixing 75-90mm

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1 each · Masonry drill bit 10mm

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VU-06Connect the water supply pipeworkFit new isolation valves onto the supply pipes if your unit doesn't already have them, using compression or push-fit joints and PTFE tape on any threaded connections. Connect flexible tap connectors between the valves and the taps, tightening by hand plus a quarter turn with an adjustable spanner - don't overtighten push-fit fittings. Check every joint is square and free from strain before moving on.

2 each · Isolation valves

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2 each · Flexible tap connectors 300mm

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1 roll · PTFE tape

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VU-07Fit the waste trap and connect to the soil pipeFit the basin waste into the vanity's basin, using plumber's putty or the supplied sealing washer under the flange. Connect a bottle trap or P-trap below, then join it to the existing waste pipe with a push-fit connector, checking the trap still holds water once tightened. Support the pipework so nothing pulls on the joints once the unit is hung.

1 each · Basin waste kit

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1 each · Bottle trap

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1 tub · Plumber's putty

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VU-08Hang the vanity unit and check it's levelLift the vanity onto the mounting rail or brackets with a second person helping - these units are heavy and awkward for one. Check it's level side to side and front to back, then drive any retaining screws through the cabinet into the rail or studs to stop it lifting off. Reconnect the flexible tap connectors and waste trap through the cabinet if you disconnected them earlier.

1 pack · Retaining screws (usually supplied)

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VU-09Turn the water back on and check for leaksTurn the stopcock back on slowly and run both taps for a minute, checking every joint underneath for drips. Leave the unit for 10-15 minutes, then check again - a slow leak often only shows once the pipe has settled. Tighten any weeping joint a small amount at a time.

VU-10Seal the edges and tidy upRun a thin bead of bathroom silicone along the join between the vanity and the wall, and along the worktop-to-wall joint, then smooth it with a wet finger or sealant tool. Remove any masking tape while the silicone is still wet for a clean line. Clear away packaging and offcuts, and vacuum up any dust from cutting the noggin or drilling.

1 tube · Bathroom silicone sealant

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