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Plumbing Inspection in Ontario, CA
22% of owner-occupied homes in Ontario have changed hands since 2018. That is an ordinary rate, which makes the ordinary mistake more likely: assuming the inspection covered the plumbing.
The one-paragraph answer
In Ontario, 22% of owner-occupied homes have changed hands since 2018. Whichever side of a sale you are on, the exclusions decide what you know: a standard inspection stops at the visible plumbing and leaves the sewer lateral to a camera survey.
Source: US Census Bureau, American Community Survey 5-year estimates, table B25038.
When Ontario moved in
With turnover near the middle, roughly one owner in five or six arrived recently. For everyone else the last time the plumbing was examined by a third party was whenever they bought.
| Owner households in Ontario | Share of all owners |
|---|---|
| Moved in 2021 or later | 6% |
| Moved in 2018–2020 | 16% |
| Moved in 2010–2017 | 25% |
| Moved in before 2010 | 53% |
Source: US Census Bureau, American Community Survey 5-year estimates, table B25038 (tenure by year householder moved into unit), 2023 release. Universe: 53,535 occupied housing units, of which 30,590 are owner-occupied. This counts when the CURRENT occupant moved in, so it measures recent moves as a share of the housing stock — not a rate of sales per year.
What the inspection will not cover
Both standards state that an inspection is not technically exhaustive and covers readily accessible, visually observable systems. That sentence is not a disclaimer at the end of the report. It is the definition of what was bought.
Source: InterNACHI Home Inspection Standards of Practice; ASHI Standard of Practice.
What it is required to cover
InterNACHI requires the location of the main water shut-off and the main fuel shut-off to be described, and whether the supply is public or private. Those are the three lines worth copying out of the report on the day you get it, because nobody looks them up until they are standing in water.
What is actually covered — because silence in a report means one thing about a covered system and something completely different about an excluded one.
What to do about it
Ask a contractor what would have to be opened up to answer the question, rather than asking for a number. A quote given without that step is a guess with a figure attached to it.
Before you accept a report, read what it did not have to cover against what it did. Then decide whether the drains outside need their own visit.
Other California towns we route in
- Rosemead 7% of owners moved in since 2018
- Chino Hills 17% of owners moved in since 2018
- Mill Valley 16% of owners moved in since 2018
- Granada Hills 11% of owners moved in since 2018
- Buena Park 16% of owners moved in since 2018
Checking a plumber in California
Checking a credential in California
California licenses are issued by the Contractors State License Board, which publishes a public search you can use before work begins. California licenses the C-36 plumbing contractor; there is no state journeyman license.
Inspection report in front of you?Read us the plumbing lines and nothing else — we do not want the document. We will route you to a contractor covering your area who can quote the items on it, and you are never charged by us. We take Ontario requests that never appeared on any inspection.
Call (888) 764-3501