What insurance do general contractors require from plumbing subcontractors?

Most general contractors require a plumbing subcontractor to carry general liability, workers' compensation, commercial auto and, on larger jobs, an umbrella, and to prove it with a certificate of insurance before the first day on site. These are contract requirements, not California law; the state requires workers' compensation once you have employees and a license bond for every licensee, and the rest is the GC's own risk management written into the subcontract.

A typical insurance exhibit asks for:

• General liability with per-occurrence and aggregate limits (commonly $1,000,000 per occurrence and $2,000,000 aggregate), with the GC and owner named as additional insureds for ongoing and completed operations, primary and non-contributory wording, and a waiver of subrogation.
• Workers' compensation at statutory limits with employers' liability limits stated in the contract, plus a waiver of subrogation in the GC's favor.
• Commercial auto liability, commonly $1,000,000 combined single limit, covering owned, hired and non-owned vehicles.
• Umbrella or excess liability on commercial, multi-family and public work, in amounts set by the contract.
• Notice of cancellation to the GC, and sometimes pollution liability for underground or sewer work.

Two cautions. A certificate only reports what the policy says; the additional insured and primary wording have to be endorsed onto the policy or the GC's compliance desk will reject it. And not every carrier offers every item, so send the exhibit to your producer before you sign. Agreeing to coverage you cannot buy is a contract problem, not an insurance one.