Plumbing contractor insurance in California

Water damage: the claim every plumber worries about

A fitting that lets go over a weekend can soak a house before anyone notices. Floors, drywall, cabinets, and the unit downstairs. Water damage is the most common large claim in plumbing, and it often shows up days or weeks after you leave.

The risks underwriters ask plumbers about:

• Water damage. Failed connections, a supply line not tightened, a water heater installed wrong, a cracked fitting inside a wall.
• Hot work. Sweating copper pipe with a torch beside wood framing, insulation or old dust. A torch fire inside a wall can smolder long after you pack up.
• Sewer and drain lines. Sewage backups, damaged laterals, and digging that hits gas, power or someone else's line.
• Gas lines. If you install or repair gas piping, expect questions. A leak can cause fire or explosion.
• Completed operations. Most plumbing claims come after the job is done, so completed operations coverage matters.

Service and repair vs new construction

How you work changes how your policy is written.

• Service and repair. Many plumbers live on service calls: leaks, water heaters, drain cleaning, fixture swaps. You are in a lot of homes, so you get a lot of chances for a small mistake to become a water claim.
• Remodel. Repiping, bathroom and kitchen remodels. More work inside walls, more hot work.
• New construction. Rough-in and finish on new homes or commercial jobs. GCs on these jobs want additional insured status and completed operations coverage, and some programs treat tract or multi-unit work very differently.

Tell the quote how your work really splits. A policy written for service work may not fit a new construction contract.

Service and repair contracts need the insurance notice

California requires home improvement contracts and service and repair contracts to include a "Commercial General Liability Insurance" notice. The notice states the name and phone number of your insurer, or says you do not carry commercial general liability insurance.

For plumbers this matters on every service ticket that counts as a service and repair contract, not just big remodels. Put the right insurer and phone number on your forms once your policy is in force, and update them when the policy changes.

This is general information, not legal advice. Check with CSLB on how the rule applies to your paperwork.

What GCs and homeowners ask plumbers for

• A certificate of insurance (COI) showing your general liability policy and limits.
• $1M per occurrence and $2M aggregate. The limits most GCs write into subcontracts.
• Additional insured. A certificate holder is not an additional insured. GCs usually want to be named additional insured, often with primary and non-contributory wording and a waiver of subrogation.
• Proof of workers' comp if you have employees, or the exemption you filed with CSLB if you do not.

Once your policy is in force, Aster sends the certificate to your GC. See our certificate of insurance guide.

Exclusions plumbers should read for

• Water damage limits. Some policies cap water damage or add a higher deductible for it. For a plumber this can be the most important line on the quote.
• Mold exclusions. Water claims often turn into mold claims. Many policies exclude mold.
• Hot work conditions. Some policies require fire-safety steps when you use a torch, or exclude hot work.
• Pollution exclusions. Sewage and backups can fall under pollution wording.
• New construction or multi-unit limits. Some programs exclude tract homes, condos or apartments.
• Subcontractor requirements. If you sub out excavation or other work, your subs may need their own insurance.

GL never covers injuries to your own workers (workers' comp), your own tools and camera equipment, your service vans (commercial auto), or the cost to redo your own faulty work. It covers the damage your work causes to others. Every quote on the board lists what is included and excluded.

CSLB rules and the online quote for C-36 plumbers

• Workers' comp. Every licensee files a workers' comp certificate or an exemption with CSLB. Workers' comp for all licensees is set for January 1, 2028. See our workers' comp 2028 guide.
• The $25,000 license bond. Every licensee carries it. It is not insurance.
• LLC licences. An LLC must carry liability insurance with at least a $1,000,000 aggregate if 5 or fewer people are on the licence, plus a $100,000 worker-wage bond. See the LLC requirement.

For non-LLC plumbers, CSLB does not require GL by law but strongly recommends it.

How the quote works: enter your C-36 license number and we find your business in the CSLB public record. Confirm you are the owner, then answer about a minute of tap-to-answer questions. Your quote board shops A-rated programs live, and prices arrive one by one with the deductible, limits, and what is included and excluded. Tap "Submit for approval" and a licensed agent handles it. Approval usually takes 30 minutes to 4 hours, depending on the insurance company. The final quote is emailed to sign, and nothing is bound until you sign. See what drives GL cost or compare other trades.