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Plumbing

43 articles

Above-Ground Sanitary Pipework Design: Part H Stack Sizing, Air Admittance Valves, Trap Seal Depths and Offset Connections

Part H discharge unit tables, 100mm stack for ≥2 WCs, AAV not suitable for primary ventilation, trap seal 75mm (bath/basin) vs 50mm, offset max 200mm from stack centreline
Bathroom Refit: Full Scope of Work, Materials List, and Regulations

Full bathroom renovation scope of work, materials checklist, first fix/second fix stages, and Building Regs (Part F, P, G)
Boiler Pressure Too High: PRV Operation, Expansion Vessel Fault & How to Reduce

Boiler overpressure: normal cold 1.0–1.5 bar, PRV set at 3 bar, expansion vessel diagnosis via Schrader valve, vessel pre-charge typically 1.0 bar, replacement sizing
Cold Water Storage Tanks: Sizing, Installation Rules & Legionella Prevention

Cold water storage tanks: sizing (minimum 100L), BS 1566, BS EN 12897 insulation, Legionella risk management above 20°C
Combi vs System vs Regular Boiler: Which Does My Customer Need?

Combi vs system vs regular boiler comparison: sizing by property, Boiler Plus requirements, and when each type is appropriate
Compression Fittings: Types, Sizes, and When to Use Them

Compression fitting types, sizes, and comparison vs push-fit and solder: when compression is required and installation tips
Condensate Pipe Installation: Building Regs Part H, Minimum 32mm Diameter, External Insulation and Termination

Approved Doc H; min 32mm internal diameter for external runs (up from 21.5mm); insulated/waterproof lagging prevents the classic winter freeze-lockout; fall ~45mm/m [verify]; termination to stack/gully/soakaway; condensate pH 3-4 → neutraliser; BS 6798
Domestic Water Pressure Explained: Bar, Flow Rate, Low Pressure Fixes and Pumps

UK water pressure: 1 bar / 9 L/min OFWAT minimum at stop tap; typical 2–4 bar; combi boiler ≥1 bar; fixes by replacing supply pipe (lead → 25mm MDPE), removing flow restrictors, accumulator or break-tank booster; direct mains pumping prohibited
Drain Testing: Air Test, Water Test & CCTV Survey Procedures

Drain testing: air test (38mm wg, 3 min), water test (1.5m head, 2 hours), CCTV survey MSCC4 grading, smoke test, preferred gradient 1:40 for 100mm pipes
Expansion Vessels: Sizing, Pre-Charge Pressure & Replacement Signs

Expansion vessels: pre-charge equals cold fill pressure (typically 1.0 bar); sizing 10–12% of system volume; waterlogged vessel diagnosis via Schrader valve
Fitting an Outside Tap: Backflow Prevention, Pipe Routing & Building Regs

Outside tap installation: double-check valve (fluid category 3, WRAS approved), Water Regulations notification, pipe lagging/stop tap, WaterSafe certification, drain-down for winter
Flexible Braided Hoses: WRAS Approval, Legionella Risk and Replacement Intervals

Flexible braided hoses: WRAS BS 6920 approval, 10-year maximum service life, Legionella risk from braided PVC, replacement programme, HSE ACOP L8 requirements
Float Valves and Ball Valves: BS 1212 Types, Pressure Classification and Replacement Procedure

BS 1212 parts 1-4 (piston/brass diaphragm/plastic/compact); HP seat for mains vs LP for gravity; warning/overflow pipe + air-gap backflow; equilibrium valves for high pressure; set level 25mm below overflow
Frost Protection for Pipework: Lagging, Trace Heating and Winter Drain-Down

Frost protection for pipework: BS 5422 insulation thickness tables, trace heating 10–15 W/m minimum, WRAS Fluid Category 5 drain-down for irrigation, minimum background heat 12°C
How Do You Install an Outside Tap? Water Regulations, Backflow Prevention, and Pipe Sizing

Water Fittings Regs notification, double check valve (Category 3 risk), frost protection, 15mm supply with isolator, WRAS-approved fittings
How Do You Select the Right Circulator Pump for a Heating or Hot Water System?

Circulator pump head/flow calculation, ErP Directive A-rated efficiency, pump curves, pumping away from expansion vessel, shower pump positive/negative head selection
How Do You Solder Copper Pipe? Step-by-Step Capillary Soldering for Plumbers

End-feed vs solder-ring fittings, flux types (BS EN 29454), step-by-step technique, lead-free solder for potable water (Water Regs 2000), common mistakes and dissimilar metal rules
Leak Detection Methods: Trace & Access, Thermal Imaging & Acoustic Equipment

Leak detection methods: thermal imaging, acoustic detection (pressurised copper best), tracer gas (N2/H2 5%), trace and access insurance, dye testing for drainage
Legionella Risk Assessment & Control: Temperature Management & Landlord Duties

Legionella management: storage ≥60°C, delivery ≥50°C within 1 minute, ACOP L8 risk assessment duty, landlord obligations, annual TMV testing requirements
Legionella Risk in Domestic Hot Water Systems: Temperatures, Dead Legs and Control

Legionella control in domestic hot water: growth 20–45°C, kill ≥60°C, store ≥60°C / deliver ≥50°C in 1 min, cold <20°C; dead leg avoidance; TMV for scald protection; ACoP L8 / HSG274 duty for landlords and HMOs
Low Mains Water Pressure: Accumulators, Break Tanks & Booster Pumps

Low mains pressure solutions: accumulator tanks (no pump), break tank with booster pump, Water Regulations compliance
Macerators and Saniflo Systems: Selection, Installation, Maintenance and Limitations

Permitted under Part G4 only with a gravity WC present; BS EN 12050; 4-5m lift / 50-100m run; 22/32mm discharge at 1:200; 5A FCU outside Zones 0-2; descaling; wipes void warranty
Mains Water Connection and Supply Pipe: Communication Pipe, Stop Tap and Water Authority Approval
New Pipework Chlorination: BS 8558 Procedure, Sodium Hypochlorite Dose Calculation, Flushing and Bacteriological Sampling

BS 8558 50mg/l free chlorine dose, sodium hypochlorite calculation formula, 1-hour contact time, triple flush, bacteriological sampling by UKAS lab before commission
Outside Tap Installation: WRAS Backflow Protection, Double Check Valve and Freeze Protection

Outside tap installation: WRAS-approved double check valve (Fluid Category 3), internal isolation valve, 15mm copper with lagging through wall, self-drain or drain-down for freeze protection; underground supply via 25mm MDPE 750mm depth
Plumbing Pipe Materials Compared: Copper, PEX, Polybutylene, MDPE and Multilayer

Copper (BS EN 1057), PEX/PB (BS 7291), multilayer PEX-AL-PEX, MDPE blue (BS EN 12201), LCS, stainless press-fit; selection by application; push-fit failure modes (insertion depth, deburr); copper within 1m of boiler; MDPE buried only; PEX expansion ~50mm/10m heated; clip spacings per BS EN 806-4
Press-Fit Plumbing: Copper vs Stainless vs Multilayer — Tools & Compatibility

Press-fit plumbing: copper vs stainless vs MLCP; jaw compatibility rules (brand-specific); BS EN 1254-7; leak-before-seal feature; pipe preparation steps
Push-Fit Plumbing Fittings: Speedfit, Hep2O & Demounting — When & How

Push-fit plumbing: insert (stiffener sleeve) mandatory for PB/PEX but not copper, Speedfit/Hep2O demounting, MLCP incompatibility with standard push-fit collets
Replacing a Radiator: Draining Down, Valve Types, Sizing Up & System Refill

Radiator replacement: isolation without full drain-down, valve compatibility (BSP tails), sizing up for heat pump (low-ΔT output tables), system inhibitor top-up, air lock prevention after refill
Shower Tray Installation: Low-Profile Trays, Waste Positions & Floor Reinforcement

Shower tray installation: low-profile tray subfloor reinforcement (18mm ply), waste position planning, P-trap vs bottle trap, 38mm water seal minimum, tile-over trays (Wedi, Schlüter) for wet room
Shower Types Compared: Electric, Power, Mixer, Thermostatic and Digital - When to Use Each
Smart Water Meters and Water Monitoring: What Plumbers Need to Know About Installation
Soldering Copper Pipe: End-Feed vs Solder Ring Fittings, Flux Selection and Safe Technique
Stopcock and Gate Valve Types: BS 1010 Classification, Replacing Under Live Pressure

BS 1010 screwdown mains stopcock, BS 5154 gate, BS EN 13959 lever isolation; 15/22/28mm DZR brass; quarterly exercise; pipe-freezer/branch-clamp live replacement; NRSWA notify for highway external stopcock
Thermostatic Mixing Valves: TMV2, TMV3 & Where They're Required

TMV guide: TMV2 for domestic, TMV3 for healthcare; set point 41°C/43°C, annual testing requirements, WRAS approval
Trace Heating Installation: BS 6351, Self-Regulating Cable, Frost Thermostat and WRAS Requirements

Self-regulating frost-protection cable; BS 6351-3 / BS EN 62395; 10-17 W/m at ΔT; frost stat +3-5°C; 30mA RCD + earthed braid; WRAS on potable; insulation mandatory; cold-start inrush limits run length
Underfloor Heating: Pipe Spacing, Loop Lengths, and Installation Guide

UFH pipe spacing tables, maximum loop lengths, manifold sizing, screed depth, and insulation requirements per BS EN 1264
Unvented Hot Water Cylinders: G3 Qualification and Installation Requirements

G3 qualification requirements, mandatory safety devices, discharge pipework specs, and Building Control notification for unvented cylinders
Water Meter Installation: WRAS-Approved Meters, Smart Meters, Sub-Metering for HMOs and Shared Supply Connections

WRAS-approved pulse or smart meters, water company pre-approval for new connections, HMO sub-metering lease clause, shared supply Section 6 Water Industry Act consent
Water Regulations: What Plumbers Need to Know About WRAS and Backflow Prevention

Water Supply Regulations 1999, WRAS approval, fluid categories 1–5, backflow prevention devices, and notification requirements
Water Softener Installation: Bypass Valves, Drinking Water & Waste Connections

Water softener installation: bypass valve requirement, 750mm min from stop cock, separate drinking supply tap, drain connection
What Size Pipe Do I Need? Domestic Plumbing Pipe Sizing Guide

UK domestic plumbing pipe sizes: when to use 15mm, 22mm, 28mm for hot water, cold water, and central heating per BS EN 806
What Size Waste Pipe Do I Need? Sizing, Minimum Falls, and Regulations

Waste pipe sizing (32mm–110mm), minimum gradients/falls, maximum run lengths, and AAV requirements per Approved Document H