Lead pipes and drinking water
The incoming pipe looks like lead and the pipes under the sink are copper. Why does the copper not prove the supply from the road is lead-free?
Copper under the sink does not prove the supply from the road is lead-free. The incoming pipe looks like lead, which is the pipe before the installation changes, and the pipes you can see under the sink are copper. Those are two observations at two places. Copper shows that someone used copper where it is visible. It does not show what is buried between the road and the house, or what remains hidden between the incoming lead and the sink. The survey has not traced the supply and has not sampled the water. The road-side supply is unproved.
Last reviewed 24 October 2026. Written for buyers in England and Wales unless this answer says otherwise. No named surveyor has signed this page. It is general guidance, not a report on your house, and not legal advice.
What is the fuller explanation?
Re-pipes often stop at the convenient point: the sink, the stopcock, or the place a floor was up. The old incoming service can be left because it belongs to a different length of pipe, sometimes outside the owner's easy reach. A bright copper trap and two copper tails are real, and they are local. The survey should describe both materials and refuse the cheerful conclusion that the lead has gone.
Tell a plumber the incoming pipe looks like lead and the sink pipework is copper, and ask them to trace the change of material. Ask the solicitor what the water company or the searches say about the supply pipe, without pretending the survey already settled it. Do not scrape the incoming pipe or cut a coupon out of it. The visible contrast is enough to keep the question open. Copper at the sink is a partial replacement at most, not a lead-free certificate for the main.
What should you ask your surveyor?
- Where did the pipe look like lead, and where did you see copper?
- Have you avoided treating the copper as proof the incoming supply is lead-free?
- What length between the road and the sink was not seen?
What are the typical next steps?
- Keep the incoming lead-looking pipe and the copper under the sink as two notes.
- Do not claim the supply from the road is lead-free.
- Ask for the change of material to be traced before you rely on the copper.
Costs vary with the building and with who you instruct. Where this page does not cite a published figure, ask the surveyor, a relevant specialist, or your solicitor for a written quote. Do not treat a forum average as the price.
Also asked about this
If the copper is stamped as copper, does that clear the main?
No. A stamp identifies the visible pipe under the sink. It says nothing about the incoming pipe that looks like lead, and nothing about the buried supply from the road. That supply was not proved lead-free. The road supply stays unproved.
Does a water softener mean the lead has been removed?
No. A softener treats water that reaches it. It does not replace an incoming pipe and it was not a sample of lead in the supply. The copper still does not prove the road main is lead-free. The incoming pipe is still the issue.