Summary: Wiring an exterior wall light: Learn how to wire an exterior wall light, prepare a new lighting circuit, fit a boxed light fitting, fit a bracketed light fitting, install an inside switch, and fit an outside switch.
The safest way to install a wall light is to run a spur from the indoor lighting circuit. It is also possible to run the spur from a socket outlet on the ring-main via an FCU. The switch should be placed on the inside of the wall and you will need weatherproof light fittings designed for mounting on an outdoor wall.
Preparing a new lighting circuit
- Cut off the power supply to the relevant circuit from the consumer unit.
- Install a spur and junction box by following one of the methods outlined in Extending Lighting Circuits. To run the spur from a ring-main socket, follow directions for Extending Circuits and Installing Fused Connection Units.
- Prepare the cable route for the spur cable from the lighting circuit or FCU to the junction box.
- Prepare the cable route from the junction box to the lighting point.
- Prepare the cable route from the junction box to the switch.
- On the inside of the wall, make a mark at about 1.8m (6ft) from floor-level and drill a hole for the cable from the chase through to the outside wall.
Fitting a boxed light fitting
If your wall light consists of a bulb between a base and transparent cover, you can fix it to the wall by the base.
- Hold the base of the light in position on the outside wall and draw around it, marking the screw holes.
- Drill and plug the screw holes.
- Feed the cable through the hole in the wall from inside and thread it through the hole in the light base.
- Screw the base to the wall.
- Prepare the cable and cores for connection and sleeve any bare earths in green-and-yellow insulation.
- Connect the live and neutral cores to separate terminals in the bulb holder and the earth to the earth terminal.
Fitting a bracketed light fitting
If your light is fixed to the wall with a bracket as in many lantern-style fittings, it will already have flex protruding from the bracket.
- Prepare the supply cable and the flex for connection.
- Connect the flex tails to the terminals in one half of a connector block.
- Connect the supply cable cores to the terminals opposite so that lives (brown), neutrals (blue) and earths are opposite each other.
- Fit a gasket around the base of the bracket to prevent water contact with the conductors.
- Screw the bracket to the wall and apply silicone sealant around the base to make a watertight seal.
Installing an inside switch
- Feed the switch cable through the hole in the back of the switch mounting box and screw the mounting box to the wall. To install a flush-mounted mounting box, follow the instructions in the project on installing sockets.
- Prepare both ends of the switch cable and the cores, insulating bare earths.
- Place a piece of brown insulation tape around the blue core to label it as live.
- At a four-terminal junction box connect the live (brown) core from the flex or lighting fixture and the brown-tagged blue core (tagged live) from the switch cable to one terminal; connect all the remaining live (brown/red) cores (from the spur cable and switch cable) to one terminal; the neutral (blue/black) cores (from the spur cable and flex) to another terminal; and the earths to the last spare terminal.
- If you are installing a new switch for the light fitting, at the switch, connect the cores to the face-plate terminals: live core to the top terminal marked TOP or COMMON, neutral core either of the bottom terminals and earth to the earth terminal in the switch mounting box.
- If you wish the light fitting to be controlled by an existing switch, replace the existing switch face-plate with a two-gang switch. Connect the cores in the new switch cable to the first gang terminals and the original switch cable to the second gang in the same way as for a new switch.
- Screw the switch face-plate to the mounting box.
Fitting an outside switch
To fit an additional switch outside, make the inside switch a two-way switch and place a one-way weatherproof switch on the outside wall. It should be positioned back to back with the inside switch.
- Drill a hole to pass the cable between the switches.
- Thread a short length of three core and earth cable through it.
- Follow instructions for installing two-way switches.
- Insulated screwdriver
- Wire cutters/strippers
- Trimming knife
- Power drill
- Masonry bit
- Exterior light fitting
- Wall plugs
- Silicone sealant
The colour-coding system for electric cable changed in 2006, make sure you read Electric cable and flex to view the new information.