A plumber's liability is set by the building rather than by the bill. A failed joint in a top floor flat can damage several homes below it, and the claim is nothing like the size of the job that caused it. Public liability answers for that damage and for the legal costs of the argument about it, and for most plumbers it is both the largest and the least negotiable line in the policy.
The water claim, and the limit it argues for
Escape of water is the defining plumbing claim: expensive, slow to settle and rarely confined to one property. A plumber working in houses may be comfortable at two million pounds, while anybody working in flats, commercial premises or through a main contractor is normally required to carry five million and would be sensible to anyway. The premium difference between those limits is small beside a single multi property claim, which is why the higher limit is the default recommendation rather than an upsell.
Hot works: the condition that decides fire claims
Soldering and torch work put a naked flame into somebody else's building, and trade policies respond with a hot works condition: combustibles cleared or protected, extinguishers to hand, and a fire watch maintained for a stated period after the last flame, commonly an hour. On many wordings it is a condition precedent to liability, which means a fire claim can be declined outright if it was not followed. It is the single most important sentence in a plumber's schedule.
Gas changes the policy, not just the price
Gas work is legally restricted to Gas Safe registered engineers, and insurers rate and word gas work separately. A plumber who touches gas appliances must be registered and must have declared it, because undeclared gas work is not merely underpriced, it is outside the cover. The registration also matters at claim: an investigator will check it and the relevant gas safety records before anything else.
What public liability leaves for other sections
Liability answers for other people. Your tools, the boiler on the floor waiting to be hung and the bathroom half installed are your own property until handover, and they belong to the tools and contract works sections. Damage to underground services, when you dig for a soil pipe or an outside tap, is limited or excluded on some trade wordings. None of that is exotic; it is simply in a different part of the schedule from the number the quote led with.
Questions people ask about plumbers public liability insurance
How much public liability insurance do plumbers need?
Two million pounds is common for domestic work and five million is the normal requirement for flats, commercial premises and main contractor work. Since a single escape of water can affect several properties, the higher limit is usually the sensible choice as well as the contractual one.
Is public liability insurance a legal requirement for plumbers?
No, though employers' liability is once you employ anybody. Public liability is required by contract: letting agents, housing associations, commercial clients and main contractors all ask for evidence before work starts.
What is the hot works condition?
It is a policy condition governing soldering and torch use: clear or protect combustibles, keep extinguishers to hand and maintain a fire watch for a stated period after the last flame. On many wordings it is a condition precedent, so a fire claim may be declined where it was not met.
Does the policy cover gas work?
Only where gas is declared and the engineer is Gas Safe registered. Gas is underwritten separately from general plumbing, and undeclared gas work leaves the exposure outside the cover rather than merely underpriced.