Kitchen Plumbing: Getting the Boring Bits Right
Waste falls, standpipes and boiling taps — the unglamorous details that decide whether a new kitchen leaks or lasts.
Kitchen plumbing is unglamorous, and it's exactly where retrofitted kitchens most often go wrong.
Waste runs need a proper fall
A sink waste needs a consistent gradient to the stack — around 1:40. In a lot of extensions, the sink ends up a long way from the original soil pipe with a waste run that's almost level, draining slowly from day one and blocking with grease soon after. Plan the run before units go in, not after.
Isolation valves on every appliance
Every washing machine, dishwasher and fridge with a water connection should have its own accessible isolation valve — when a machine floods, you want to shut off one valve, not the whole house.
Standpipes done properly
Washing machine and dishwasher hoses fitted too low, or pushed too far into a standpipe, siphon dirty water back into the drum. The hose needs a high loop and the standpipe needs an air gap — a two-minute detail that prevents a smell nobody can trace later.
Boiling water taps
Popular in kitchen refits — they need a fused spur, cabinet space for the tank, and in a hard water area, a scale filter that actually gets changed on schedule.