looking to extend socket to small playshed at rear of house. Distance is about 25 m. What is the best cable to use and what way should it be laid. Looking to cost job first. Was thinking it needs to be armoured cable.
The cable size used is dependent upon the load to be supplied as well as the distance and the method of installation. What do you mean by playshed? Are we talking child's Wendy house or a teenagers game room, console, TV, maybe heater (beer fridge). If it is a Wendy house type arrangement how often are you actually going to be needing to use this power supply. It could be a lot of expense for minimal usage. For example assume a 2.5mm Armored cable was calculated to be suitable http://www.screwfix.com/p/prysmian-lv-armoured-6493x-3-core-cable-2-5mm-x-25m-black/38769 a 25m length could be bought for approx. £40, but that does not include any fixings, glands, cable connectors, accessories for the play house itself, suitable means of connection in the main house, labour, testing certification of the fixed work. If it has to be buried or go over any pathways gates etc 25m may not be long enough. An external socket and an outdoor grade extension lead may be more practical for occasional use. Think in terms of a 25m hook up cable used for motor homes and caravans on campsites. http://www.amazon.co.uk/Caravan-Motorhome-Camping-Approved-Hookup/dp/B008L1EHVS a couple of connectors at the house a playshed could allow easy connection and removal as a when needed.