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Plumbing Inspection in San Mateo, CA
San Mateo is settled. Only 15% of owner households moved in during 2018 or later, which means most of the plumbing here has not been looked at by anybody in a long time.
The one-paragraph answer
Only 15% of owners in San Mateo arrived in 2018 or later, which makes this settled ground. Long tenure does not change the scope: a standard inspection covers what can be seen and operated, and the drain line beyond the house is excluded from it.
Source: US Census Bureau, American Community Survey 5-year estimates, table B25038.
When San Mateo moved in
Where houses stay put, an inspection is a rare event, and the report on file — if there is one — describes a building that has since had a decade or more of ordinary use.
| Owner households in San Mateo | Share of all owners |
|---|---|
| Moved in 2021 or later | 4% |
| Moved in 2018–2020 | 10% |
| Moved in 2010–2017 | 27% |
| Moved in before 2010 | 59% |
Source: US Census Bureau, American Community Survey 5-year estimates, table B25038 (tenure by year householder moved into unit), 2023 release. Universe: 53,985 occupied housing units, of which 27,986 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
The water heater is covered in some detail by both standards — and InterNACHI is equally explicit that nobody is required to measure its capacity, temperature or adequacy, or to test the relief valve. It is looked at, not operated.
Source: InterNACHI Home Inspection Standards of Practice; ASHI Standard of Practice.
What it is required to cover
The fixtures are a live test rather than a look. InterNACHI requires the inspector to run the water at every faucet, flush every toilet, and check that every sink, tub and shower drains; ASHI requires functional flow and functional drainage. If a fault shows up in ordinary use, this is the part of the inspection that finds it.
The rest of what an inspector must do is set out here. It is shorter than the excluded list and it is the half that tells you what a finding is worth.
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.
The two standards are published in full and worth ten minutes: what is excluded, what is covered, and why the drains outside the house are a separate instruction.
Other California towns we route in
- Rancho Cucamonga 19% of owners moved in since 2018
- San Gabriel 9% of owners moved in since 2018
- Sausalito 15% of owners moved in since 2018
- Bakersfield 23% of owners moved in since 2018
- Altadena 12% 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. Not only inspection items: San Mateo gets routed whatever is needed.
Call (888) 764-3501