installation
Outside taps and garden plumbing
Fitting an outside tap costs £120 to £250, and takes an hour or two. Water regulations require a double check valve on the supply, which stops garden water being drawn back into the drinking supply, and that is the part a self-installed tap usually misses.
What this covers
What it costs. An outside tap costs £120 to £250 fitted off an existing internal cold pipe, and takes an hour or two. Full cost breakdown.
What the job covers
- Outside tap installation with double check valve
- Frost proof and self-draining taps
- Standpipes and garden supply runs
- Isolating and draining taps for winter
- Supplies to garden rooms and outbuildings
What is involved
The standard installation tees off an internal cold pipe, usually under the kitchen sink, passes through the wall and terminates in a bib tap outside. Between the tee and the wall go an isolating valve, so the tap can be shut off and drained in winter, and a double check valve, which is a non-return device required by the Water Supply Regulations. Without it, a hose left in a water butt or a bucket of weedkiller creates a route for contaminated water back into the house supply when the mains pressure drops.
Frost is the other consideration. An outside tap that stays charged with water through a hard winter will split, and the split is usually inside the wall. The simple answer is an internal isolating valve and a habit of closing it in November with the outside tap left open to drain. The better answer is a self-draining frost proof tap, which sits with its valve seat inside the warm wall and empties the spout each time it is closed.
A supply to a garden room or an outbuilding is a bigger job: the pipe has to be buried at 750mm depth against frost, run in continuous barrier pipe with no buried joints, and marked. That is worth doing properly at the time the trench for the electrics is open.
Outside tap installation with double check valve, one of the jobs a outside taps specialist is hired for.
Choosing someone for the job
Confirm a double check valve is included, because it is a regulation requirement and it is the part that gets omitted. Ask whether an internal isolating valve is being fitted so the tap can be drained for winter. If the run to the tap crosses an unheated garage or void, ask how it will be insulated.
Common questions
Do I need permission for an outside tap?
No permission, but the installation must comply with water regulations, which means a double check valve on the supply. Some water companies ask to be notified.
How much does an outside tap cost to fit?
£120 to £250 for a standard installation off an existing internal pipe. More where the tap is a long way from a suitable supply or the wall is solid stone.