Short definition
A homeowner plumbing inspection is a periodic systematic walkthrough of the home’s plumbing — every visible pipe, fixture, valve, and supply line — to spot problems early. It’s observation, not action: you’re producing a checklist of what’s working, what’s aging, and what needs fixing. Different from annual maintenance (which is doing) and from regulatory inspections (which are during construction).
What it is
Three different things share the word “inspection,” and homeowners conflate them:
- Homeowner inspection: you walking through your own house with a checklist. Annual or biennial. The output is a written list of items in three buckets — fine, aging, failing.
- Annual plumbing maintenance: action-oriented version — drain the water heater, swap the flapper, descale the aerator. See annual plumbing maintenance.
- Regulatory inspection: rough-in / underground / final inspections by a permit office during construction. See rough-in inspection stages.
The homeowner inspection sits upstream of maintenance. You inspect first to know what to act on.
A good inspection produces three columns:
- Fine — working as expected, no concern this cycle.
- Aging — working but showing wear; flag for the next 6–12 months.
- Failing — fix now or call a pro.
Why it matters to a homeowner
The walkthrough is free and catches problems while they’re still cheap:
- New homeowner / first year after closing: a baseline inspection establishes a service log. Photos of every visible pipe, every shut-off, the water heater nameplate, the main shut-off location.
- Long-term homeowner: annual catches drift — corrosion that wasn’t there last year, a slow drip at a supply stop, crawlspace pipe insulation falling off.
- Approaching retirement / sale: knowing what’s failing lets you stage the major repairs while you still have steady income, instead of inheriting them as emergencies.
- Seasonal home (Methow, San Juans, Hood Canal): pre-winter inspection plus winterization is the difference between a normal spring opening and a flooded cabin.
What to look for, by area:
Visible piping
- Green corrosion on copper joints — pinhole risk forming.
- White scale buildup at unions or stops — limescale, especially Eastside and Spokane.
- Old galvanized steel still in service — plan a repipe (term in keyword index).
- In-wall pipe nail / screw piercings — the pro repair includes a nail plate.
Fixtures
- Toilet flappers older than 5 years (silent leakers) — see silent toilet leak.
- Drips at supply stops — tighten or replace.
- Slow drains at any fixture — diagnose vs. fix.
Water heater
- Active leak at base (replace, don’t repair).
- Corrosion at fittings (monitor).
- Earthquake straps loose or absent — WA L&I requires two; see strap water heater WA.
Crawlspace (most WA homes)
- Pipe insulation degraded or missing in cold zones — replace before freeze season.
- Standing water at low point — leak detective work, paired with best leak detector for crawlspace.
Cadence
- Routine: annually or biennially.
- After major weather event (deep freeze, atmospheric river): targeted re-inspection of at-risk areas.
- Before extended absence: full inspection plus winterize plus shut off main.
- After purchase / move-in: full first-year baseline.
Cost data
- DIY: $0.
- Professional walkthrough (different from a permit-inspection): $150–$400.
- Pre-purchase plumbing inspection: $300–$500 standalone, often $700–$1,500 with sewer scope add-on. See pre-purchase plumbing inspection.