Common Claims Handled by Plumbers Insurance (And How to Prevent Them)

Plumbing work comes with real‑world risk: a press‑fit fails after turnover and soaks a ceiling, a torch ignites framing during a repipe, a customer trips over hoses, or a social post triggers an advertising‑injury dispute. Plumbers Insurance—a package anchored by Commercial General Liability (CGL) and complemented by tools & equipment (inland marine), commercial auto, workers’ comp, and often Contractors Pollution Liability (CPL) and Contractors Professional Liability (E&O)—is built for exactly these moments. 

Below, we break down the most common plumber claims, what your policy addresses (and what it doesn’t), and practical prevention steps you can put in place this week.

1) Water Damage (during work & after completion)

Why it’s common: Water damage remains one of the most frequent and costly construction‑site losses—and plumbing scopes are a primary exposure. Completed operations claims often arise months after you leave, when a slow leak reveals itself. 

How CGL responds: Third‑party property damage caused by your operations or products‑completed operations, is core CGL territory (subject to exclusions and limits). Note: CGL typically won’t pay to redo your defective work (“your work” exclusion), though it may cover resulting damage to others’ property. 

How to prevent:

• Implement a Wet Work Permit on any job that opens water systems (pre‑job shut‑off verification, pressure‑test logs, active leak checks, end‑of‑day valve inspections, emergency plan).
• Use insurer‑backed water‑damage prevention checklists and routine inspections (roaming leak checks, drain protection, and overnight shut‑offs where feasible).

2) Hot‑Work Fires (soldering/brazing)

Why it’s common: Open flame and heat in finished spaces can ignite concealed combustibles; many losses occur after crews leave the area. 

How CGL responds: Fire/smoke property damage or third‑party bodily injury to others caused by your operations is generally contemplated by GL—again, subject to terms and exclusions. 

How to prevent:

• Run an NFPA 51B‑compliant Hot‑Work Program with permits, combustible clearance, shielding, and documented fire watch. Use the NFPA permit template. 
• Train crews on fire‑watch duties and re‑check for smoldering after work stops.
• Prefer flame‑free joining methods (e.g., pressing) when code and specs allow—many hot‑work permits explicitly prompt evaluating safer alternatives first.

3) Third‑Party Slip/Trip/Fall (premises liability)

Why it’s common: Hoses, cords, wet floors, and open flooring create hazards for occupants and visitors.

How CGL responds: Bodily injury to non‑employees caused by your operations (including defense and settlements) is a core GL coverage. Average slip‑and‑fall claims run around $20,000, underscoring why prevention matters. 

How to prevent:

• Practice jobsite housekeeping and keep passageways clear per OSHA construction standards; post wet floor and hazard signage as needed.
• Manage cords/hoses (ramps/covers), protect open work areas, and stage materials away from walk paths.

4) Damage to Finishes & Contents (third‑party property damage)

Why it’s common: Tight spaces, heavy tools, and in‑home work make cabinets, floors, counters, and furnishings vulnerable.

How CGL responds: Property damage to others caused by your operations is typically covered, subject to exclusions such as damage to your property and workmanship. 

How to prevent:

• Use drop cloths, corner guards, floor protection, and spotters in crowded areas to prevent damage.
• Photograph the conditions before and after work; move or protect valuables; maintain a customer walk-through checklist.

5) Completed‑Operations Leaks (weeks or months later)

Why it’s common: Failures may present after occupancy (e.g., pinhole leak, mis‑sized gasket, missed torque).

How CGL responds: Products‑completed operations handles third‑party BI/PD occurring after you’ve finished—key for plumbers. Remember: the policy typically does not cover the cost of redoing your work. 

How to prevent:

• Log pressure tests, verify torque/press indicators, and document fixture/appliance make/model/SN.
• Institute 24‑hour and 72‑hour post‑turnover checks on higher‑risk scopes (owner/GC walkthroughs).

6) Pollution, Sewage & Category‑3 Water (often not covered by GL)

Why it’s common: Drain cleaning, sewer backups, and water‑damage jobs can involve bacteria/mold.

How CGL responds: Most CGL forms contain absolute/total pollution exclusions; mold/bacteria are frequently excluded or tightly limited. Many contractors buy Contractors Pollution Liability (CPL) to close this gap.

How to prevent:

• Use Category‑3 water protocols (containment, disinfection, appropriate PPE) following ANSI/IICRC S500 principles. 
• Control cross‑connections and backflow (testing/maintenance of backflow assemblies) to protect potable water and avoid third‑party claims.

7) Personal & Advertising Injury (copyright, libel/slander)

Why it’s common: Social posts, website images, and local ads can trigger IP or defamation allegations.

How CGL responds: CGL includes personal & advertising injury for specified offenses (subject to exclusions). 

How to prevent:

• License photos/fonts/music; keep receipts.
• Institute a social media policy; avoid comparative claims that imply falsehoods; get legal/risk review for major campaigns.

8) Professional Errors (specs, layout, design‑assist) — E&O, not GL

If you provide design/spec selection, sizing, venting/layout, or code‑compliance advice that a client relies on, a claim may fall under Contractors Professional Liability (E&O), which is usually claims‑made. Policies and definitions vary; review how “professional services” is defined. 

Prevention: Use written RFIs, follow manufacturer/code guidance, confirm scope on ASIs/SK drawings, and keep decision trails.

9) Vehicle Accidents — Commercial Auto, not GL

GL does not cover on‑road accidents. If your business owns/uses vehicles, you need commercial auto insurance for liability and (optionally) physical damage coverage. 

Prevention: MVR checks, defensive‑driving refreshers, documented cell‑phone policies, and (where offered) telematics programs.

Risk‑Management Strategies That Actually Lower Losses (and Premiums)

• Stand up permit programs: Hot‑Work (NFPA 51B) and Wet‑Work permits with logs, photos, and end‑of‑day valve checks.
• Housekeeping & access control: Keep passageways clear; barricade work zones; post wet‑floor signs; manage cords/hoses.
• Document everything: Pre‑job site photos, protection setup, pressure‑test results, sign‑offs, and customer walkthroughs.
• Know your policy: Understand GL limits/aggregates, completed‑ops, your‑work exclusions, pollution carve‑outs, and when you need CPL/E&O.
• Leverage carrier loss‑control: Many insurers supply water‑damage and hot‑work checklists—use them and keep proof.

Why This Matters Now

The pricing heat is in liability lines: global commercial rates fell 4% in Q2‑2025 on average, but casualty (liability) rose ~4% globally and ~9% in the US—a trend linked to higher claim severity and “nuclear” jury awards. Well‑documented controls and clean loss runs help keep you insurable and competitive. 

Take Control of Your Risk—And Your Claims

Understanding the claims plumbers actually face—water damage, hot‑work fires, slip‑and‑fall, finished‑surface damage, advertising injury, plus pollution and professional‑services exposures—is the first step. The next is prevention: wet‑work and hot‑work permits, solid housekeeping, documented pressure tests, and careful marketing practices. That combination reduces claims and helps stabilize premiums.

Ready to tighten your protection? Get a tailored quote from Plumbers Insurance US and build a package—GL + tools & equipment + auto + workers’ comp, with CPL/E&O where needed—that fits your jobs, contracts, and budget.