13A Switched Sockets — Single and Double Gang, Screwless and Metal Clad for UK Electricians

The 13A switched socket outlet is the single most frequently installed electrical accessory in UK domestic and light commercial work. Every room in a domestic rewire needs them; every office fit-out, kitchen renovation, and extension project demands them in quantity. Understanding the differences between socket types — 1G vs 2G, SP vs DP, standard vs screwless, surface vs flush, plastic vs metal clad — allows you to specify correctly first time, avoid call-backs, and offer customers a finish that matches their interior.

This guide covers the socket types UK electricians actually install day-to-day, wiring requirements under BS 7671:2018+A2:2022, protection requirements, and the products available from APM Electricals.

Understanding 13A Socket Outlet Specifications

Single Pole (SP) vs Double Pole (DP) Switching

All 13A socket outlets must switch the line conductor. The difference between SP and DP lies in whether the neutral is also switched:

• SP (Single Pole): Switches line only. Compliant for general use. When switched off, neutral remains connected — acceptable under BS 7671 Regulation 537.3 for domestic socket outlets.
• DP (Double Pole): Switches both line and neutral simultaneously. Required where equipment connected may present a hazard if neutral-energised when off. Common in professional/commercial installations, heating circuits, and where RCD protection is not provided on the circuit.

In practice, most Knightsbridge, Click, and MK sockets sold in the UK are DP switched as standard, providing belt-and-braces compliance for all installation types.

1-Gang (1G) vs 2-Gang (2G)

A 1G (single gang) outlet fits a single back box — 86mm × 86mm standard UK single plate. A 2G (double gang) outlet requires a double-width pattress — 86mm × 146mm. In bedrooms and lounges, a 2G is almost always specified over two 1G outlets: it requires one back box, one cable run, and presents a cleaner finish.

BS 7671 has no minimum socket count for domestic rooms but recommends guidance (e.g., kitchen 6–8 outlets minimum). The IET On-Site Guide Appendix E provides room-by-room recommendations.

Flush vs Surface Mounting

Flush mounting into a metal back box (see our article on Metal Back Boxes and Dry Lining Boxes) gives a flat finish against the wall surface. Surface mounting uses a moulded plastic pattress box screwed to the wall face — appropriate for masonry walls where chasing is impractical, garages, utility rooms, and first-fix situations before plastering.

Standard vs Screwless Finish

Standard sockets use a visible central screw to fix the faceplate to the back box. Screwless designs use a clip or sprung mechanism hidden behind the faceplate — the plate clips into a concealed mounting frame. Screwless finishes (Knightsbridge Square Edge, Flat Plate, Matt White, Brushed Chrome) are increasingly specified in new-build and high-specification domestic work.

Wiring 13A Socket Outlets

Cable Selection

Standard ring final circuit: 2.5mm² Twin & Earth (6242Y grey). Spur from ring: 2.5mm² T&E. Radial circuit serving up to 20m²: 2.5mm² T&E on 20A RCBO or 4.0mm² on 32A RCBO.

Terminate cores using appropriate ferrules or bootlace crimp connectors where the screw terminal is smaller than the stranded conductor spread. Earth sleeving (green/yellow) is mandatory on the bare CPC.

Ring Final Circuit Rules (BS 7671 Appendix 15)

A standard ring final circuit serves floor areas up to 100m² (domestic). The ring must be verified as a true ring — both ends returned to the same MCB/RCBO. Live, neutral, and CPC must each form a continuous ring; the CPC ring must have continuity at every socket outlet.

Spurs: an unlimited number of non-fused spurs (one socket per spur) may be taken from the ring. Fused spurs (via 13A FCU) may serve multiple outlets or appliances. See our article on Fused Connection Units and Fused Spurs for FCU selection.

RCD Protection Requirements (18th Edition Amendment 2)

Regulation 411.3.3 (18th Ed, Amendment 2, effective 28 Sep 2022) requires RCD protection for all socket outlets rated up to and including 32A in domestic premises where the socket may be used by ordinary persons. This applies to new installations and alterations. Options:

• 30mA RCD protecting the entire circuit (in consumer unit)
• RCBO per circuit (combines MCB + 30mA RCD in one module)
• RCD-protected socket outlet at the point of use (e.g., Axiom/CED WRCDSSK2)

For commercial premises and offices, RCD protection at 30mA is required for socket outlets accessible to the public or non-electrically skilled persons.

Socket Types and When to Use Them

Standard White Plastic — Domestic New-Build and Renovation

The most commonly installed type. Curved-edge and square-edge profiles from Knightsbridge, Click Curva, and Click Mode suit standard domestic settings. Modern 18th Edition installs should ensure the circuit is protected by RCBO or whole-circuit RCD at the consumer unit.

Screwless Designer Finish — High-Specification Domestic

Flat-plate polished chrome, brushed chrome, matt white, and matt black screwless sockets are now standard on premium refurbishments and new-build show homes. The faceplate clips onto a concealed mounting frame; no visible screws. Higher trade price but often specified by architect or main contractor.

Metal Clad — Garages, Workshops, and Commercial

Steel faceplates with robust construction and IP2X protection by default. Suitable for garages, plant rooms, workshops, and light industrial applications. Must be earthed via the back box (metal back box to metal faceplate earth continuity screw). Surface mounting on galvanised or PVC surface pattress is common in these environments.

Weatherproof / IP66 — Outdoor Installations

For outdoor socket outlets, see our article on Outdoor Electrical Sockets and Garden Wiring. IP66 weatherproof sockets must be used where exposed to weather; 30mA RCD protection is mandatory for outdoor socket outlets.

Installation Best Practice

Back Box Depth

Standard single back box: 25mm or 35mm depth. With 2.5mm² T&E plus earth sleeving, a 25mm box is often adequate; 35mm depth preferred where multiple cables terminate. Dry-lining (plasterboard) boxes must have a secure fixing method — toggle fixings or friction pads.

Cable Entry and Protection

Where cable enters from below the socket (common in first-floor sockets), ensure the cable is not pulling tight onto the back box entry grommets. Use grommets in all knock-out entries to protect the cable sheath. In zones where mechanical protection is required (BS 7671 Reg 522.6), cables must be run in zones or protected by conduit or steel capping.

Termination Torque

Follow manufacturer torque specifications. Most standard 13A socket terminal screws require 0.8–1.0 Nm. Under-torqued connections cause resistive heating; over-torqued screws can crack the insulation. A calibrated screwdriver or torque screwdriver reduces call-backs on heating/tripping faults.

Testing After Installation

After wiring, test before applying power: continuity of ring (R1+R2 measurement), polarity test (line to correct terminal), earth continuity (CPC connected). After energising: correct operation of RCD/RCBO, socket polarity with a plug-in tester. For landlord certificates and EICRs, see our article on EICR Landlord Electrical Safety Inspections.

Recommended Socket Outlets from APM Electricals

All four products below are active and available to trade. Prices are inclusive of VAT.

Pricing vs Screwfix and Toolstation

APM Electricals stocks the full Knightsbridge socket range at competitive trade pricing. The curved-edge range (1G) undercuts typical high-street trade pricing on entry-level sockets while offering the Knightsbridge brand quality and BS 1363-2 compliance. Screwless sockets are competitive against equivalent screwless ranges from Schneider Electric, MK, and BG Nexus.

Summary

• Most UK 13A sockets are DP switched, meeting all domestic and commercial applications
• Ring final circuits on 2.5mm² 6242Y T&E; radials on 2.5mm² (20A) or 4mm² (32A)
• 18th Ed Amendment 2 (Sep 2022): 30mA RCD protection mandatory for domestic socket outlets
• Curved-edge range: budget new-build and rewire work
• Screwless range: high-specification domestic and commercial fit-out
• Metal clad: garages, workshops, industrial and utility environments
• Always verify ring continuity and polarity before commissioning

Also in this series: Metal Back Boxes | Fused Connection Units | USB Charging Sockets | Outdoor Sockets | WAGO Connectors | PVC Conduit

Shop 13A Sockets at APM Electricals

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APM Electricals
24 Western Avenue, Acton, London W3 7TZ
Phone: 020 8702 8080
Web: www.apmi.uk
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