Lead pipe turns up in Central London more often than most people expect. The stock is old, the supply infrastructure under these streets is old, and while lead has not been used for new water pipes for decades, a great deal of what was installed before then is still buried, still boxed in, and still carrying water into flats today.
If you have found grey pipe in a cupboard and you are trying to work out what to do about it, this page covers three things: how to identify it, who is likely to be responsible for which part of it — which is genuinely a split question and one you must confirm rather than assume — and what replacement actually involves in a listed terrace or a mansion block.
How to tell if you have lead
Lead is easy to identify once you know what you are looking at, and easy to confuse with other things if you do not.
Colour and surface. Dull grey, matt, no shine. Copper is orange-brown, or green where it has corroded. Galvanised steel is grey too, but it has a dull silvery, slightly mottled look and it is threaded at the joints.
The scratch test. Scrape gently with a coin. Lead goes bright silver and shiny underneath. Galvanised steel stays dull grey. This is the most reliable quick test.
Shape. Lead is soft. It bends in smooth, rounded curves rather than sharp elbows, and it often looks slightly irregular, as though it has sagged. Old lead runs frequently have gentle bows in them. It also dents under a thumbnail — copper does not.
Joints. Traditional lead joints are bulbous wiped joints, made by hand with molten solder, not neat machined fittings. If you see a lumpy swelling where two pipes meet, that is a wiped joint and it is a strong signal.
Sound. Tap it. Lead is dull and dead. Copper rings.
Look in the obvious places: where the supply enters the property, under the kitchen sink, around the stopcock, under floorboards near the front of the building, in the basement or vault of a terraced house. In a flat, the internal pipework is often long since copper or plastic while the incoming supply from the street is still lead — that is a very common pattern in Victorian conversions across Bayswater and Paddington.
Why people replace it
Two reasons, and it is worth being straight about both.
Water quality. Lead can dissolve into drinking water, and the general public health position in the UK is that lead in drinking water should be minimised and lead supply pipes should be replaced where practicable. That is not new or contested. What varies enormously is how much lead any given pipe actually contributes, which depends on the water chemistry, the length of the run, and how long water sits in the pipe. Water utilities in England treat supply water to reduce lead uptake — but treatment reduces the problem, it does not remove the pipe. If you want to know what is in your water, your water utility can usually advise on testing rather than you relying on guesswork or on anything you read online, including here.
Performance and reliability. This is the reason we most often see it come up in practice. Lead is soft. Over a century it deforms, narrows and gets knocked. Old lead supply pipes are frequently a real contributor to poor flow in period flats, and they are vulnerable to damage from any work nearby. If you are chasing weak taps and there is lead in the run, that is a plausible cause — our guide to low water pressure in a London flat covers how to test properly before assuming.
What we would not do is tell you your pipe is dangerous in order to sell you a replacement. If it is lead, the honest framing is that replacement is generally worth doing, it is usually worth doing at the same time as other work rather than as a standalone dig, and the urgency depends on your circumstances rather than on a slogan.
The responsibility question — and why you must confirm it
This is the part people get wrong, and it matters because it decides who pays.
The supply of water to a property is generally split into two parts. There is the section of pipe running under the public highway from the water main, and there is the section running from the property boundary into and through the building. In broad terms, the pipework on the public side tends to be the water utility's responsibility, and the pipework from the boundary onwards — the supply pipe — tends to be the property owner's. That is the general shape of it in England.
But it is genuinely more complicated than that in Central London, and we are not going to pretend otherwise:
Shared supply pipes. A great deal of the terraced stock here was built with one supply pipe serving several houses, which were then converted into flats. That single pipe may now serve a dozen households. Who is responsible for a shared supply pipe, and what happens when one owner wants it replaced and the others do not, is not a question with a tidy general answer.
Flats and demise. In a leasehold flat, the boundary between your responsibility and the freeholder's is set by your lease, not by a general rule. Pipework serving multiple flats is commonly a common part; pipework serving only yours is commonly yours. Commonly is not always. Read the lease.
Utility schemes. Water utilities in England have, at various times, operated schemes relating to lead pipe replacement, and the terms, eligibility and availability differ between companies and change over time. We are not going to name a scheme, quote a cost, or tell you what you are entitled to, because that would be guessing at your expense. Contact your water utility directly and ask them what applies to your property. They will also usually tell you what they believe they own on their side.
The practical sequence: establish where the pipe runs, establish where the boundary is, read the lease if you are leasehold, and ask the water utility what their position is on their section and on any assistance. Do that before you commission anything. It is free and it can change the whole scope.
What replacement actually involves
The work divides into the bit inside the building and the bit outside it, and they have completely different difficulty profiles.
Internal pipework. Replacing lead runs inside a flat is ordinary plumbing, complicated only by access. New pipe in copper or an approved plastic, new stopcock, proper connections, and the awkward part is usually getting to it under floors and behind boxing. In a period conversion, this is where the surprises live — runs that go somewhere unexpected, sections that turn out to serve a neighbour, and joints hidden inside a wall.
The incoming supply from the boundary. This is the significant one, and it is a groundwork job as much as a plumbing one. It typically involves excavating to expose the pipe, running a new supply — usually in blue MDPE — and connecting it. Where the route crosses a front garden, a lightwell, a vault, a paved forecourt or a pavement, the reinstatement is a real part of the job.
Moling versus digging. Where ground conditions allow, a new supply can sometimes be moled or drawn through with only a hole at each end rather than an open trench. Whether that is possible here depends on what else is in the ground — and in Central London there is a great deal else in the ground.
Partial replacement. If only part of the run is replaced and lead is left in the rest, you have not solved the water-quality question. This is one of the reasons for establishing ownership first: replacing your half while the utility's half stays lead may not achieve what you wanted. Ask them.
The Central London complications
Four things make this harder here than in a suburban semi.
You cannot always dig where the pipe runs. Front lightwells, vaulted pavements, York stone paving, original tiled paths, railings and steps all sit over supply routes in this stock. Where the property is listed, works affecting its special character can require listed building consent, and in conservation areas planning controls are tighter. Lifting and reinstating an original path or a stone step is not a trivial detail — it may be the most controlled part of the whole job. Establish the position before you plan the route.
Nobody knows where anything is. Records for supply pipes in Victorian stock are frequently absent. The pipe rarely runs where you would expect. It may enter through a vault, cross under a neighbour's ground, or take a route that made sense to somebody in 1880. Locating the run is genuinely part of the work.
The highway. Any work in or under the public highway involves the highway authority and, for the utility's side, the water company. That is not something a plumber arranges casually. If the route crosses the pavement, that is a conversation with the council and the utility, and it has its own timescale — check with them rather than budgeting on optimism.
Leases and consent. In a flat, altering the supply arrangement usually needs freeholder or managing-agent consent, often through a licence to alter, and where the pipe is shared with other flats, the freeholder has an obvious interest. In a block, replacing a shared lead run is likely to be a communal works question — and if the cost passes the statutory threshold per leaseholder, consultation under Section 20 of the Landlord and Tenant Act 1985 may apply. Your managing agent should confirm.
When to do it
The sensible answer is: when the floor is already up.
If you are planning a bathroom refurbishment, a kitchen, or a wider refurbishment, that is the moment to deal with lead inside the flat. The floors are open, the walls are open, and the marginal cost is a fraction of what it would be as a standalone job that requires opening everything up again. The same logic applies after a leak — if a burst has already opened a floor, replacing tired old pipe while you are in there is usually the cheapest it will ever be. Our guide to a burst pipe in a mansion block makes the same argument from the other direction.
If you are not doing other work, the trigger is usually either performance — poor flow you have traced to the supply — or a decision to deal with the water-quality question. Either is a reasonable reason. Neither is an emergency.
What to ask before you commission anything
Where exactly does the pipe run, and how do you know? What is being replaced and what is being left? Is any lead remaining in the run after this work? Who is responsible for the section on the other side of the boundary, and has the water utility been asked? What consents apply — freeholder, listed building, highway? What is the reinstatement, and is it in the price? A quote that does not answer the reinstatement question is not a quote.
How we handle it
We start by finding and identifying the pipe properly rather than assuming from a photo, then tell you what we think is yours, what is likely to be the utility's, and what you need to confirm with them and with your lease. Where the job is inside the flat, our plumbing work starts from £80 and the price is fixed before we start. Where it involves excavation, consents or highway, it is quoted properly with the reinstatement included, because that is the part that catches people out.
We work across W1, W2, NW8 and W9, including the older terraced and block stock in Little Venice and Maida Vale. Send a photo of the pipe and the cupboard it is in through the quote form, or reach a plumber in Bayswater or Little Venice the same way.