Plumbers & electricians in Catford

Rushey Green runs north to south along the valley floor with the shopping parades either side of it, and the ground rises away only slowly, west towards Forest Hill and east towards Downham. North of the town centre the streets running up to Hither Green are late Victorian and Edwardian bay fronted terraces. South and east of that, Bellingham is a nineteen twenties cottage estate built by the London County Council on former farmland, short terraces and semis of solid brick with long back gardens.

Two very different kinds of house, and they behave differently in almost every way except one. They share a floor. Both sit on flat ground inside the Ravensbourne catchment, and both drain into a system that has to shift rainwater off a lot of hard surface before any of it reaches the river.

Heating and wiring here age much as they do anywhere else in south east London, so plenty of the work is ordinary. A boiler repair in Catford in the first cold week of the year, a shower room taken back to brick, an electrician in Catford fitting a consumer unit or an EV charger beside a Bellingham driveway. The drains are the part that is local.

Why heavy rain comes back up the lowest drain in the house

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There are two drainage systems under most of these streets and it matters which one a pipe belongs to. Foul drainage carries the WC, the sinks, the bath and the washing machine, at a steady rate whatever the weather does. Surface water drainage carries rain off the roofs and yards through the gullies, and its load goes from nothing to enormous in ten minutes. In some streets the two run separately, in older parts they end in one combined sewer, but either way the rainwater side fills first in a downpour, and on flat ground near a river there is very little fall to help it along. Once the sewer below is full to the top the water in your drain has nowhere to go, so it stops running, and then it comes back.

From inside the house that looks specific rather than dramatic. The gully outside the kitchen door fills to the rim and sits there. The downstairs WC gurgles and the level in the pan lifts and drops with nobody having flushed. Whatever is lowest and connected is where it shows, usually the ground floor WC or the outside gully in a terrace, the shower waste in a lower ground flat. The tell is the timing. If it only happens in heavy rain and runs perfectly on a dry day, that is the sewer surcharging rather than a blocked drain in Catford wanting a rod through it, and clearing a pipe that was never blocked changes nothing next time it rains.

Three things genuinely help. Keeping the gullies and rainwater outlets clear is dull and it works, because a gully half full of silt cannot take a sudden load even when the sewer below still has room. Knowing what has been joined to what matters as much, since rainwater plumbed into the foul drain, which happens easily when a patio or a new downpipe is connected to whatever pipe was nearest, sends hundreds of litres into the drain carrying your WC. The third, for a house that sits genuinely low and has had water in before, is a non return valve on the outgoing drain so flow can leave and cannot return. That is real work on the underground pipework and it needs a chamber you can reach, so the run is worth surveying first to confirm which system the drain belongs to. Fitted on the wrong branch it protects nothing.