A festoon made from fabric cable and E27 lamp holders looks different from the thin Christmas lights from the DIY store: sturdier cable, bigger bulbs, more character. For the garden or terrace, you can put one together yourself from just a few parts. Here's the planning, from length to installation.
Calculate the length and number of lamp holders
First measure the stretch you want to light – for example 6 metres between two points. The usual spacing between two lamp holders is 50 to 100 cm: 50 cm looks dense and festive, 100 cm calmer and more generous. For a 6-metre stretch with 75 cm spacing, the maths gives 8 lamp holders (600 cm ÷ 75 cm = 8), plus the two end points, which usually also have a lamp holder. As a rule of thumb: number of lamp holders = (length in cm ÷ spacing in cm) + 1. For the cable length itself, add 1 to 2 metres at each end so the string can hang loosely (a sag of 5 to 10% of the length looks more natural than a taut cable) and so you can anchor it at the fixing.
Through lamp holders instead of single lamp holders
Festoon lights need through-wired lamp holders: E27 lamp holders with two cable entries, so the cable runs in on one side and out the other instead of ending at each lamp holder. Electrically, that means a parallel circuit – every lamp holder gets the same voltage, and if one bulb fails, the others stay lit. For outdoor use, silicone through-wired lamp holders or ones with a rubber seal are the right choice, because they seal the cable entries against moisture. You'll find an overview of suitable lamp holders under Lamp holders, and cable for outdoors under Fabric cable – filter there specifically for damp-proof versions or read the article Fabric cable for bathrooms and outdoors.
IP65 is a must outdoors
Every component of the festoon lights – lamp holders, cable, plug and any switch – must reach at least IP65 (dust-tight, protected against water jets) for outdoor areas with direct exposure to rain. If the string hangs under a continuous canopy or a pergola with a solid roof, IP44 (protection against splashing water) is enough. At the socket: the socket itself must also be suitable for outdoor use and protected by an RCD (30 mA). Open joints between two lengths of cable, or a plug connection that isn't expressly designed for outdoor use, belong under a roof or in a weatherproof box.
Fixing: tension wire or direct suspension
For longer stretches (from about 4 to 5 metres), a separate stainless steel tension wire carries the weight, while the festoon lights are attached to it with cable clips or eyelets – that takes the strain off the power cable itself and stops the cable stretching or sagging over time. For short stretches up to about 3 metres, the fabric cable can also be tensioned directly if its cross-section is large enough (at least 0.75 mm², better 1.0 to 1.5 mm² for many lamp holders and longer stretches), provided the end points are solid (hooks in masonry, not a loose fence). Fixing points should be rated for the total weight of cable, lamp holders and bulbs – with 8 lamp holders with bulbs and several metres of cable, that quickly adds up to 2 to 3 kg.
Light bulbs for outdoors
For outdoor festoon lights, LED is practically the only option: little heat, reliable start even in the cold, low consumption with many lamp holders in a row. Globe bulbs (G95, G125) are the classic shape for festoon lights and are cosiest in warm white light (2200 to 2700 Kelvin). With 8 lamp holders and a 4-watt LED in each, total consumption is about 32 watts – no problem for any normal socket. Matching globe bulbs are in Globe bulbs.
Assembly step by step
Cut the cable to the calculated length, allowing extra for sag and fixing. Connect the first lamp holder: remove the sheath, feed the wires into the strain relief of the through-wired lamp holder, close the terminals (with ferrules for fine-stranded fabric cable – see the articles Fabric cable cross-section and Stripping fabric cable). Run the cable on to the next lamp holder position and repeat there until all lamp holders are in place. Finally, fit a plug or connect the string to an existing plug-in light. Test it on a normal indoor socket before hanging it up for good; only then mount it outdoors and screw in the bulbs.
Order everything together
Cable, through lamp holders and accessories in the right colour and length can be put together piece by piece in the configurator; if you'd rather have a ready-made package, you'll find matching combinations under Kits. Extra tools such as a ferrule crimper or cable clips are available under Accessories.