To extend a garden tap, tee the cold feed, run insulated pipe at safe depth, add isolation and backflow, then mount the new tap.
Thinking of moving water to the far bed, greenhouse, or a patio sink? This guide shows how to extend an outside tap cleanly, without leaks or code headaches. You’ll see the planning, the parts, trench work, and the neat finish. If you can cut pipe, use a drill, and take your time, you can get a tidy new outlet that’s ready for hoses or irrigation.
Planning First: Route, Depth, And Protection
Good planning saves digging twice. Map your route from the existing supply to the new point. Keep bends gentle and joints accessible. Note where you’ll cross paths, flowerbeds, paving, and any other services. Decide whether you’ll hide the run underground or clip it along a fence in insulated trunking. Underground looks cleaner and stays cool, while a surface run is quicker and easier to maintain.
Next, choose materials. Blue MDPE is the usual buried choice; it’s tough and fits compression fittings. For short surface runs, copper or barrier PEX in conduit works well. You’ll also want an isolation valve indoors, a double check valve for backflow security, and a frost-proof hose union tap at the far end. Add pipe insulation at entries and any exposed sections.
| Item | Recommendation | Notes |
|---|---|---|
| Pipe Type (Buried) | Blue MDPE PE80/PE100 | Durable; compression fittings |
| Pipe Size | 20–25 mm MDPE or 15 mm copper/PEX | Match supply and flow needs |
| Bury Depth | About 750–1350 mm | Protects from frost and damage |
| Backflow Safety | Double check or hose tap with built-in check | Stops contamination |
| Isolation | Full-bore lever valve indoors | Easy winter shut-off |
| Drain/bleed point | Drain cock on the branch | Let trapped water out before frost |
| Lagging | Closed-cell insulation at entries/exposed runs | Prevent freezing |
| Fixings | Clips every 0.5–0.8 m | Stops pipe sag and rub |
How To Extend Garden Tap: Step-By-Step Build
1) Isolate, Drain, And Mark The Line
Shut the main stop tap. Open the outside tap to release pressure. Mark the new route with paint or string. If you plan to dig, call before you dig and check for buried services. Lift slabs carefully and store soil neatly so backfill is easy later.
2) Tee Into The Cold Feed
Find the cold pipe serving your current outside tap, usually 15 mm copper or 15/22 mm plastic. Cut a clean section and fit a tee. Add a full-bore lever valve and a drain cock on the new branch so you can isolate and empty the run each winter. Keep joints accessible indoors where possible.
3) Choose The Run: Buried Or Surface
Buried run: Dig a trench wide enough for comfortable laying. Bed the pipe on sand, not rubble. Aim for a steady depth near the frost line. Slip the pipe through a duct where it passes walls or paths, and seal ends after inspection. Keep the pipe away from electric and gas lines, and give it smooth bends rather than sharp kinks.
Surface run: Clip copper or barrier PEX along a fence or wall inside a protective conduit. Keep it shaded, insulated, and protected from strimmers. Add a few unions so sections can be swapped later.
4) Pull Pipe And Make Joints
For MDPE, cut square, insert liners, and tighten compression fittings by hand then a quarter turn with a spanner. For copper, deburr and use quality compression or press fittings. For PEX, use the matching sleeve or crimp system. Keep underground joints to a minimum; where required, wrap them for protection and place them in accessible boxes.
5) Fit Backflow Protection And The New Tap
Fit a double check valve on the branch upstream of the outside line, or use a hose union tap with integral check protection. Mount the tap on a solid plate or standpipe at a sensible height. If irrigation is connected, raise the backflow device above outlets or choose the device grade that matches the risk.
6) Pressure Test, Flush, And Lag
Before backfilling, cap the end and bring the line up to mains pressure. Check every joint for damp spots. Flush until clear, then insulate entries and any exposed sections. Backfill with sand around the pipe, then soil, and reinstate slabs. Label the indoor valve so anyone can shut it quickly.
Extending A Garden Tap To A Distant Corner — What Works
Long runs add friction losses, which drop flow at the new outlet. Use the largest practical bore for the main stretch, keep bends gentle, and minimise fittings. If the tap will feed sprinklers or a soaker hose, test output with a bucket and a timer to check you’re meeting the needs of your setup. Where pressure is marginal, a simple smart schedule that waters in stages can help more than a pump.
Choosing Pipe Materials For Your Setting
MDPE (buried): Tough, flexible, and purpose-made for underground. Compression tees and elbows make it DIY-friendly.
Barrier PEX (surface/ducts): Light, quick to route, and fine in conduit. Keep it out of sunlight and protect it from abrasion.
Copper (short surface runs): Rigid, neat, and easy to clip. Insulate well outdoors and avoid low spots that trap water.
Mounting Options: Wall Plate, Post, Or Standpipe
A wall plate elbow keeps things tidy near a shed or greenhouse. Where no wall exists, fix a treated timber post or a metal standpipe. Set the outlet high enough for a bucket under the spout. Leave enough space for a hose connector and a service loop so strain doesn’t pull on the fittings.
Regulations, Safety, And Good Practice
Outside outlets can siphon dirty water back into the drinking supply. That’s why backflow protection sits in the plan. A double check valve, or a tap with the device built in, is standard for hose points; see hose union tap backflow protection for what’s expected. Keep outlets above spill levels, and never run a hose end into ponds or chemical containers.
Depth also matters. A buried service needs frost cover and protection from spades. Most UK guidance points to a trench depth in the three-quarter metre range, deeper in cold pockets, and you can check minimum burial depth guidance for the typical 750–1350 mm range. Where depth isn’t possible, insulate and duct the pipe as it enters the building.
| Item | Typical Spec | Qty/Range |
|---|---|---|
| MDPE Pipe | 20–25 mm PE80/PE100 | Route length + 10% |
| Compression Fittings | Tees, elbows, couplers | Plan + spares |
| Isolation Valve | Full-bore lever type | 1 |
| Backflow Device | Double check or HA/DB type | 1 |
| Hose Union Tap | Frost-proof preferred | 1 |
| Insulation | Closed-cell outdoor grade | As needed |
| Trench Sand | Soft bedding material | 2–4 bags |
| Fixings & Clips | UV-safe where exposed | 1 pack |
| Tools | Pipe cutter, spanner, drill | — |
Troubleshooting After You Turn It On
Drips At Compression Joints
Shut the branch, open the drain, and remake the joint. Check the pipe insert is fully seated and the olive is clean. Tighten a touch more, but don’t crush the pipe. If a fitting weeps again, replace the insert and nut.
Low Flow At The New Tap
Look for a half-closed isolation valve or a kink in a tight bend. Long runs on small-bore pipe drop flow. Upgrading the main stretch to 25 mm MDPE usually helps. Also swap any narrow hose nozzles for open-bore connectors.
Air Hammer Or Noise
Secure the pipe with closer clip spacing. Add a slow-closing bib tap or a mini arrestor close to the outlet. Keep pressure sensible and avoid fast shut-off valves on hoses.
Freeze Risk
Shut the indoor valve, open the outside outlet, and crack the drain cock so the branch empties. Fit a tap jacket and check insulation at wall penetrations. If the line must stay live, use a frost-resistant tap and lag thoroughly.
Maintenance That Keeps It Leak-Free
Before winter, isolate and drain the branch. In spring, re-pressurise and check joints. Replace washers in good time, and keep a spare hose connector at the tap. Once a year, spin the isolation valve so it doesn’t seize. Every few seasons, lift a slab or open an access point to check the buried section is dry and sound.
When To Call A Pro
If the route crosses other services, if you can’t hit safe depth, or if backflow protection options look confusing, bring in an approved plumber. A short site visit can confirm the route, device choice, and pipe size. You can still do the trench and reinstatement to keep costs in check.
Cost And Time: What To Expect
Parts for a typical run of about 15–25 m land around the price of a modest tool haul, even with a frost-proof tap and new valve gear. Most DIYers spread the job over a weekend: day one for trenching and pipe, day two for pressure tests and making good. Weather and ground conditions set the pace more than anything else.
Final Checks Before You Backfill
Confirm The Must-Haves
Is the isolation valve accessible? Does the branch have a drain point? Is backflow protection fitted? Are entries lagged? Run through the checklist before you drop the last shovel of soil.
Project Notes That Help Later
Keep a sketch of valves, depths, and fittings, plus receipts and photos. When you file the notes, write “how to extend garden tap” on the folder so the details don’t vanish. If you track projects in a notes app, tag one entry “how to extend garden tap” to group the parts list, trench photos, and test results.