Fit a push-fit tee to add a new tap supply

Isolate your water, tap into an existing pipe with a push-fit tee, and run a new supply safely to your tap.

PT-01Plan the route and check accessDecide where the new tap will go and pick the nearest existing pipe carrying the right water type (hot or cold). Work out the route from that pipe to the new tap, and check you can get at both ends without major disruption. Look for the shortest, most direct run, avoiding sharp bends where possible.

PT-02Find your stopcock and isolate the waterFind your stopcock, usually under the kitchen sink, and check it turns freely before you start. Turn it off now, even before you get near the pipe, so you're not searching for it in a panic later. This is the single most important step if anything goes wrong.

PT-03Drain the pipeworkOpen the lowest tap on the system (or a drain-off valve if there is one) to empty the pipe you're working on. Hold a towel or small bucket under the point you'll cut, as there's always some residual water left in the pipe. Leave the tap open until you've finished cutting.

1 each · Bucket

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1 each · Old towel or rag

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PT-04Work out what's behind the wall or ceiling on your routeIf your new pipe run crosses a stud wall or ceiling, find out what you're dealing with before you drill anything. Run a stud detector or a magnet along the surface — a magnet will catch on screw heads fixing plasterboard to timber studs, but will do nothing over a plain plasterboard face between metal studs. Tap along the wall: a dull thud usually means a stud or solid material behind, a hollow sound means empty cavity. A small pilot hole tells you for certain — timber dust means a timber stud, fine grey swarf means metal, and if the drill goes straight through with no resistance at all, you're in the cavity between studs or fixing to dot-and-dab plasterboard.

1 each · Stud detector or magnet

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PT-05Choose the right pipe clip fixings for your wall typeInto solid brick or block, drill with a masonry bit sized to your wall plug, insert the plug fully, then drive the screw in. Into a timber stud, use a wood screw driven into the centre of the stud, not the edge. Into a metal stud, never use a wall plug or wood screw — a wood screw will strip straight through 0.5mm steel — use a self-drilling metal-stud fixing instead. For a run between studs, or on dot-and-dab plasterboard, use a toggle or hollow-wall anchor rated for the pipe's weight; for dot-and-dab specifically, make sure the fixing is long enough to reach the solid masonry behind the dabs, not just the plasterboard face.

6 each · Wall plugs (masonry)

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6 each · Screws 32mm

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4 each · Self-drilling metal-stud fixings

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4 each · Toggle or hollow-wall anchors

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4 each · Long fixings for dot-and-dab (75mm)

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6 each · 15mm pipe clips

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PT-06Drill your fixing and route holesCables and pipes can run almost anywhere in a wall or ceiling, not just in the 'safe zones' you might have read about. Use a cable and pipe detector first, but still treat every hole as if something could be there — cheap detectors miss deep cables, cables in metal conduit, anything behind metal-backed plasterboard, and they get confused by a metal stud frame. If you have any doubt at all, isolate the relevant circuit at the consumer unit before drilling, and make sure your water is still off at the stopcock before you drill anywhere near other pipework. Drill your fixing holes and any holes needed to pass the pipe through a stud or joist, keeping well clear of the edges.

PT-07Cut into the existing pipe and fit the teeMark the pipe where the tee will go, allowing enough straight, clean pipe on each side for a proper push-fit connection. Cut the pipe square, deburr the cut ends, and check the pipe is round and undamaged before pushing it into the tee. Push each end fully home until it seats against the internal stop — you should feel it click or stop firmly.

1 each · Push-fit tee 15mm

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1 each · Pipe cutter

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PT-08Run the new pipe and clip it in placeFeed the new pipe along your planned route, through any holes you've drilled, and offer it up to check the fit before fixing anything permanently. Clip the pipe every 500mm to 800mm on horizontal runs using the fixings you chose in step 5 for each wall type. Keep the pipe running square and level where it will be visible.

3 m · 15mm pipe

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PT-09Fit an isolation valve near the new tapFit a small service (isolation) valve into the pipe run close to where the new tap will connect. This lets you turn off just this tap in future without shutting off the whole house. Push-fit and quarter-turn service valves are both fine for this — fit it so the handle is easy to reach.

1 each · 15mm push-fit isolation valve

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PT-10Connect the new tapConnect the final length of pipe to the tap's tail using a proper compression or push-fit fitting, with PTFE tape on any threaded joints. Only use fittings marked as complying with the Water Supply (Water Fittings) Regulations 1999 — look for a WRAS approval mark on the packaging. If the new tap is outside or could allow water to flow backwards into the mains (such as a hose connection), fit a double check valve to prevent contamination, and check with your water supplier if you're unsure whether the work needs to be notified to them.

RULES

1 each · PTFE tape

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1 each · Double check valve

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KNOW THE RULES

Water fittings and any work that could risk contaminating the mains supply are covered by the Water Supply (Water Fittings) Regulations 1999. Use WRAS-approved fittings and fit backflow protection where needed.

PT-11Turn the water back on and testClose any open taps you used to drain the system, then turn the stopcock back on slowly. Check the tee, the new joints, the isolation valve and the tap connection closely for drips, and run the new tap for a minute to check the flow and look again for leaks. Recheck all joints again after 30 minutes, as some push-fit joints show a small weep only once under full pressure.

PT-12Tidy upInsulate any exposed pipe run through an unheated loft, garage or cavity to stop it freezing in winter. Sweep up any drilling dust or pipe offcuts, and dispose of the old pipe cuttings and packaging responsibly. Give the new tap a final check once everything is put back together.

2 m · Pipe insulation lagging

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