How to install an outdoor tap

An outdoor tap must be connected to the mains cold supply (not the hot, and not via a softener if you have one). Locate the rising main — usually the first cold feed after the stopcock under the sink. Plan a route from there through the wall to the outside tap position.

Turn off the mains water at the internal stopcock. Drain the pipe by opening a tap downstairs. Mark the drill position on the outside wall for the tap backplate — ideally below a kitchen window for easy pipe routing.

Drill through the wall using a long masonry bit (22mm or a proprietary core bit for outside tap kits). Angle slightly downward from inside to outside so water drains away from the wall naturally.

Fit the outside tap backplate onto the wall (plugs and screws supplied in the kit). Thread the wall pipe through the hole. Inside, install a 15mm tee into the rising main using compression fittings or push-fit. Run a branch pipe to the wall penetration.

Before the wall penetration, fit a double check valve — a small brass or plastic non-return valve (included in most kits, or £5–£15 separately) that prevents garden hose backflow contaminating the mains. Also fit an isolating valve inside so you can drain the outdoor tap in winter.

Seal around the wall penetration with exterior silicone. Turn the water back on, check all joints, and open the outdoor tap briefly to flush debris from the new pipework. In autumn, close the indoor isolating valve and open the outdoor tap to drain the section of pipe — this prevents frost damage to the external fittings.