Plumbing Inspection Checklist for Seattle Homes – Prevent Costly Water Damage Before It Starts

Standard plumbing inspections typically cost between $150 and $300, depending on property size and scope. A basic visual inspection runs lower, while comprehensive inspections with specialized services like sewer camera scoping add to the cost. In Seattle, many inspectors recommend including sewer line camera inspection because of the prevalence of older clay pipes and root infiltration issues. Factors affecting price include home age, number of fixtures, and accessibility of plumbing components. Pre-purchase inspections may cost more than routine maintenance checks. Always confirm what the inspection includes before scheduling.

Active water leaks represent the biggest red flag in any home inspection. Water damage leads to mold growth, structural rot, and expensive repairs. In Seattle, look for signs of sewer line problems like multiple slow drains, sewage odors, or soggy yard areas. These often indicate collapsed clay pipes or root infiltration. Other major concerns include outdated materials like galvanized steel pipes that restrict water flow, evidence of previous water damage with temporary repairs, and improperly vented drain systems. Failed water heaters and corroded supply lines also signal immediate attention and replacement needs.

A complete inspection checklist covers water supply systems, drain and waste systems, water heaters, and fixtures. Include checks for leaks, corrosion, proper venting, and code compliance. Document pipe materials, water pressure readings, and drain flow rates. In Seattle, add sewer line condition assessment due to aging infrastructure and tree root issues. List all shut-off valves and verify operation. Check for proper fixture installation, secure mounting, and functional operation. Include exterior items like hose bibs, sprinkler systems, and main water service condition. Note any previous repairs, unpermitted work, or safety hazards requiring immediate attention.

The four main inspection types are visual inspections, functional testing, specialized diagnostics, and code compliance reviews. Visual inspections examine accessible components for obvious defects. Functional testing runs water through systems to verify proper operation. Specialized diagnostics include sewer camera scoping, pressure testing, and leak detection using acoustic equipment. Code compliance reviews confirm installations meet current Seattle building standards. Pre-purchase inspections combine all four types. Maintenance inspections focus on visual and functional aspects. Permit inspections verify new work meets code. Each type serves different purposes but follows similar inspection protocols and documentation standards.

Passing inspection requires meeting local building codes and proper installation standards. All plumbing must be accessible for inspection, with no active leaks or code violations. In Seattle, you need proper permits for most plumbing work beyond basic repairs. Water pressure must fall within acceptable ranges, typically 40 to 80 psi. Drain systems need proper venting and correct slope. Fixtures must be securely mounted and functional. Water heaters require proper venting, temperature and pressure relief valves, and seismic strapping in some cases. All work must use approved materials with proper connections and support.

Houses fail inspections for active leaks, sewage backups, or major code violations. Improperly vented drain systems, missing cleanouts, and cross-connections between potable and non-potable water cause failures. In Seattle, collapsed sewer lines and significant root infiltration often fail inspections. Outdated materials like lead pipes, unvented fixtures, and improperly installed water heaters raise red flags. Missing permits for previous work can delay closings. Inadequate water pressure, backflow prevention issues, and unsafe gas line installations also result in failures. Most issues are repairable, but some require extensive work before passing reinspection.