Plumbing in flats and conversions in Barnet, Finchley and Edgware

Why is a flat different from a house?

In a house, every pipe inside the walls is yours. In a flat, the cold main, the soil stack, the rainwater pipes and sometimes a cold water tank in the roof serve several homes at once, and a fault in one flat shows up in another. Fixing it is partly a plumbing question and partly a question of who is allowed to touch what.

Barnet has every kind of flat: Edwardian and Victorian houses split into two or three in Finchley and Golders Green, 1930s mansion blocks along the main roads, council-built estates, and new blocks of several hundred homes in Colindale, Hendon and Mill Hill. Each brings its own plumbing habits.

Whose pipe is it?

For a leasehold flat, the lease decides. A common pattern is that pipes serving only your flat are yours once they branch off the shared supply, while anything shared stays with the freeholder, who recovers the cost through the service charge. Leases differ, so read yours or ask the managing agent before booking anyone.

When a leak from one flat damages the flat below, whoever owns the pipe that failed repairs the pipe. The damage is a separate question: the building's insurance often covers it, and the upstairs leaseholder or the freeholder pays only where the lease says so or someone was careless.

Where is my stopcock?

Not always in your flat. In a converted house the main stopcock is often under the stairs or in the ground floor flat's kitchen, and the upstairs flats may have only a small valve on their own branch, if that. In a purpose-built block there may be a valve in a riser cupboard on the landing, in a service duct or in the basement plant room. Find it now, label it and tell the people you live with.

If there is no way to isolate your own flat, ask the plumber to fit a valve. It turns a future leak from a building problem into a flat problem.

Water is coming through from upstairs. Who do I tell?

Three people, in this order: the occupier above, so they can turn their water off; the managing agent or freeholder, so the building's record and insurance are triggered; then a plumber for your own side. Keep every message, date and photograph. If the flat above is let, its tenants may not know who their landlord's agent is, which is where the freeholder's records help.

I rent. Do I call the landlord or a plumber?

Call the landlord or their agent first. For most tenancies in England, section 11 of the Landlord and Tenant Act 1985 makes the landlord responsible for keeping the water supply, basins, sinks, baths and toilets in repair, along with the heating and hot water installations. A tenant who books their own plumber for a repair the landlord should have done may not get the cost back. Report it in writing, give the landlord a chance to act, and keep a copy.

What makes a converted house awkward?

Victorian and Edwardian houses were built for one family. When they were split, the plumbing was added to rather than redesigned, so a bathroom may sit above a neighbour's bedroom, a waste pipe may cross another flat's ceiling, and one soil stack may serve three kitchens and three bathrooms. Macerator toilets were often used where a proper soil connection was impossible.

If the conversion was done before modern rules, the sound insulation between floors is often thin, which makes a dripping overflow or a gurgling waste audible next door. Ask the plumber whether a repair can be done from within your flat or needs access elsewhere.

What about tall blocks and mansion blocks?

Older mansion blocks often keep a cold water tank in the roof that feeds every flat by gravity, so the top floor has the weakest flow. Newer blocks pump water up from a tank in the basement, and a problem with that pump stops water for everyone, which is a job for the management company rather than a plumber you book yourself. Some new developments supply heat and hot water from a central plant, so a fault with hot water may not be inside your flat at all.

Any gas appliance in a flat, and any work on gas pipework, is only for an engineer on the Gas Safe Register. If you smell gas, leave the building and ring 0800 111 999.

What should the enquiry cover?

• your postcode and which floor you are on
• whether the building is a converted house, a mansion block, an estate block or a new development
• whether the fault seems to be inside your flat or in something shared
• who the managing agent or freeholder is, if known
• whether you own, rent privately or rent from the council or a housing association