Electrics and gas
The cold-water header tank in the loft has no lid or lagging. What contamination and freeze risk was seen, and what water test was not taken?
The risks seen are contamination and freezing. The cold-water header tank in the loft has no lid, so dust, debris and insects can enter the stored water, and no lagging, so the tank and its pipes are exposed to loft temperatures. The water test that was not taken is any sample or analysis of that water. The survey saw an open, unlagged tank. It did not test potability, metal content or bacteria. The finding is the missing lid and the missing insulation, not a laboratory result.
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?
Header tanks feed stored cold water to parts of an older plumbing system. An open top is a direct path for whatever blows around the loft. Missing lagging is a winter problem: a freeze in that tank or the pipes off it. Both are visible defects of protection, and both can be described without pretending a sample bottle was filled. The surveyor may also note a stale smell or staining. Smell is still not a test.
Ask a plumber to refit a close-fitting lid and to lag the tank and the pipes, and ask whether this tank still feeds anything you drink or only the bathroom. That question matters because the kitchen tap may be on a different pipe, which the survey has not proved. Tell the solicitor the loft tank was open and unlagged. Do not claim a water test the report does not contain. The survey's facts are the missing cover, the missing lagging, and no sample taken.
What should you ask your surveyor?
- Did you see the header tank without a lid and without lagging?
- Was any water sample taken from it, or explicitly not?
- Which pipes off the tank did you actually trace, if any?
What are the typical next steps?
- Record the open, unlagged header tank as seen.
- Do not invent a water-quality result for that tank.
- Ask a plumber to cover and lag it, and to say what it feeds.
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 kitchen tap is mains-fed, does the loft tank stop mattering?
Only for the taps that are truly on the mains, which the survey has not fully traced. The tank still has no lid and no lagging, and no water test was taken from it. Bathroom feeds can still come from the tank.
Does a new ballvalve mean the water was tested?
No. A ballvalve is a filling control. It does not lid the tank, lag it, or sample the water. The contamination and freeze risks that were seen remain the survey's point. No sample was taken from the open loft tank.