Plumbing Contractor Insurance in Washington State

Plumbing contractors in Washington face a risk profile dominated by one thing: water. Water damage claims are by far the most frequent and most costly category of liability for plumbers, and the Pacific Northwest's aging housing stock and wet climate amplify the exposure. A single improperly soldered joint, a cross-threaded fitting, or a missed connection can release hundreds of gallons of water into a home in minutes, causing damage that cascades through floors, walls, and ceilings. Claims of $50,000 to $150,000 are routine for residential water damage, and commercial plumbing failures can reach seven figures.

The completed operations risk for plumbers is significant and long-lasting. A supply line connection that slowly drips behind a wall can foster mold growth for months before discovery. When the homeowner traces it back to your work, you face not just the water damage claim but a mold remediation claim that can easily double the total cost. Washington's six-year construction defect statute under RCW 64.50 means homeowners have a wide window to bring these claims, and plumbing defects are among the most commonly cited in construction defect litigation.

Job-site risks extend beyond water damage. Plumbers work in confined spaces, trenches, and crawl spaces where injuries from falls, struck-by incidents, and ergonomic strains are common. Torch work for soldering copper creates fire risk, and working around existing electrical and gas systems adds additional hazard layers. Commercial plumbers working on multi-story buildings face height exposure, heavy equipment operation, and coordination risks with other trades.

Washington requires plumbers to hold a valid plumber certificate from L&I, with journey-level and master plumber designations requiring examination and documented experience. As a specialty contractor, you need a $15,000 surety bond. But the real financial exposure lies in the claims. Operating a plumbing business in Washington without comprehensive liability coverage means one bad fitting could cost you your home, your savings, and your business.