Electrical Materials
Cable, back boxes, consumer units, MCBs, RCBOs, and wiring accessories for a domestic extension, including what each component does and what to check when your electrician specifies it.
Back Boxes: Metal Flush, Dry Lining, and the Depth Mistake That Costs You a Day
Complete UK guide to electrical back boxes: metal flush vs dry lining, depths from 16-47mm, earthing rules, prices from around 55p each, and the plasterboard offset calculation nobody explains.
Cable Sizing Guide: Which Cable Size Do You Need?
Decision guide for choosing between 1.5mm, 2.5mm, 4mm, 6mm, and 10mm twin-and-earth cable in a UK domestic extension. Covers derating through insulation, ring vs radial, and Part P.
Data Cable for UK Homes: Cat5e, Cat6, Cat6a, Cat7, Cat8 - What to Actually Buy
Plain-English guide to ethernet cable for UK extensions: why Cat6 is the standard, when Cat6a is worth the upgrade, why Cat7 and Cat8 are marketing traps, and the CCA cable scam to avoid.
PVC Conduit: Oval vs Round, When You Need It, and the Cable-First Rule Your Electrician Knows
Complete UK guide to PVC conduit for domestic electrical work: oval for wall chases, round for surface runs, sizes, BS 7671 rules, and prices from around 44p per metre.
Consumer Units: What Every Homeowner Needs to Know Before Second Fix
The complete UK guide to consumer units (fuse boxes): dual RCD vs all-RCBO configurations, metal enclosure rules, SPD requirements, brands, and installed costs from £380-720.
Earth Sleeving: The £6 Roll That Stops Your Extension Failing Inspection
Green/yellow PVC earth sleeving explained: why bare CPC must be covered, the two BS 7671 regulations that demand it, sizing by cable, and current UK prices from Screwfix, Toolstation, and TLC Direct.
Heat-Shrink Tubing: The UK Electrician's Guide for Homeowners
What heat shrink tubing is, when it's a legal substitute for a junction box (it isn't), and what BS 7671 actually requires. UK pricing from £4.40 to £25 covered.
LED Downlights for Kitchen Extensions: Fire Rating, Spacing, CCT and What to Buy
The full UK guide to LED downlights: when fire-rated is legally required, IP65 for kitchens, 4000K vs 3000K, the ceiling-height ÷ 2 spacing rule, and current 2026 prices.
MCBs (Miniature Circuit Breakers): Ratings, Types, and Why Brand Matters
UK guide to MCBs: Type B vs Type C trip curves, correct ratings for every domestic circuit, brand compatibility rules, and retail prices from £1-5 each.
RCBOs: The Protective Device That Stops One Fault Taking Out Your Whole House
UK guide to RCBOs: Type A vs Type B, circuit sizing, brand compatibility, Amendment 3 bidirectional rules, and prices from £12-30 per device.
Socket Faceplates: Finishes, USB-C, and the Back Box Depth Trap
UK guide to socket faceplates: white plastic from £1.65, brushed chrome from £7, USB-C sockets, brand quality rankings, and how many you actually need per room.
Surge Protection Devices (SPDs): The BS 7671 Default Most Old Boards Don't Have
What an SPD does, why BS 7671 Amendment 2 made it the domestic default, Type 1 vs 2 vs 3 explained, and what to specify for your extension consumer unit.
SWA Cable: The Steel Wire Armoured Guide for Garden Rooms, Garages and Outdoor Circuits
Steel wire armoured cable for buried outdoor circuits explained: BS 5467, burial depth, CW glands, banjo earth tags, voltage drop, current ratings and 2026 prices from £1.80 to £7.75 per metre.
Switch Faceplates: Gangs, Ways, Dimmers, and the LED Trap Nobody Warns You About
Complete UK guide to light switch faceplates: 1-way vs 2-way, dimmer LED compatibility, smart switch neutral wire problem, prices from £1.09, and every mistake to avoid.
1.5mm Twin and Earth Cable (6242Y): The UK Lighting Circuit Standard
Everything you need to know about 1.5mm T&E cable for lighting circuits: what 6242Y means, current prices (around £55-60 per 100m drum), brands, and the EPS insulation mistake that ruins cables.
2.5mm Twin and Earth Cable (6242Y): The UK Socket Circuit Standard
Everything you need to know about 2.5mm T&E cable for socket circuits: ring vs radial explained, current prices (around £79-84 per 100m drum), brands, and the derating trap in insulated walls.
4mm Twin and Earth Cable (6242Y): The Middle Cable for Long Radial Runs
When 2.5mm isn't enough and 6mm is overkill: 4mm T&E for kitchen island, garage and garden room circuits. Voltage drop maths, derating traps, current UK prices £140-165 per 100m drum.
6mm Twin and Earth Cable (6242Y): Cooker and Shower Circuit Wiring
Complete guide to 6mm T&E cable for cooker, hob, and shower circuits: when 6mm is enough vs 10mm, derating through insulation, current UK prices from £100-125 per 50m drum.
10mm Twin and Earth Cable (6242Y): When You Need It and Why
Complete guide to 10mm T&E cable for big induction hobs and electric showers: when 10mm is required vs 6mm, current UK prices around £190-£200 per 50m drum, and the back box trap that catches DIYers.
USB Sockets: Wattage, Back Box Depth, and the Decision You Make Before First Fix
UK guide to USB charging sockets: USB-A vs USB-C, 12W to 63W tiers, back box depth requirements, retail pricing across white and brushed steel finishes, and the two electrical safety issues most homeowners never hear about.