Quick answer
A general home inspection touches plumbing lightly — but in this region's older housing stock, plumbing is where five-figure surprises hide: galvanized supply lines, original sewer laterals, dying water heaters, and basements that flood. This checklist covers what to check yourself and what to insist gets inspected before you waive anything.
- Identify the supply pipe material — it changes the whole risk picture.
- Find and test the main shutoff valve; a seized valve is a red flag in itself.
- For pre-1980 homes, a camera inspection of the sewer lateral is worth every penny.
When do these checks happen?
The quick items during your showings and final walkthrough; the deeper items during the inspection contingency window. In competitive MD/DC markets with shortened contingencies, knowing this list cold lets you triage fast.
The checklist
- 01° Identify supply pipe material at exposed basement runs (galvanized steel and polybutylene are budget items, not dealbreakers — but price them).
- 02° Find the main water shutoff and confirm it actually turns.
- 03° Check the water heater's data plate for age — 10+ years means budget for replacement soon.
- 04° Look for an expansion tank on the water heater and a pressure-reducing valve (PRV) on the main — both are code items in many local jurisdictions.
- 05° Run the highest shower while flushing a toilet — a big pressure drop suggests corroded or undersized supply lines.
- 06° Open every under-sink cabinet: stains, warped shelves, or fresh paint only there tell a story.
- 07° Check the sump pit: is there a pump, does the float move freely, where does the discharge go?
- 08° Scan basement walls and floor for efflorescence (white mineral bloom) — the fingerprint of past water.
- 09° For pre-1980 homes, order a sewer-lateral camera inspection — root intrusion and clay-pipe failures are the classic five-figure surprise.
- 10° Ask for water heater, softener, and any plumbing-permit paperwork — permitted work is a good sign about everything else.
The waived-inspection gamble
Waiving inspection on a 1950s row house means buying its galvanized lines, original lateral, and unknown water history sight-unseen. If you must waive, at least do the walkthrough items yourself — they take fifteen minutes.
Trusting fresh paint
A newly painted basement in an otherwise dated home deserves extra scrutiny, not less. Paint is cheaper than drainage work — check the sump, the corners, and the smell.
Proof, process & local validation
- Tario's licensed plumbers (MD PLB & GFC #92636; VA & DC licensed) perform pre-purchase plumbing evaluations across the region.
- One company for the whole mechanical picture — HVAC and plumbing evaluated in a single visit, since 2013.
- 4.9-rated on Google; call (410) 314-1161 to schedule within your contingency window.
Methodology: Checklist assembled from the pre-purchase evaluations Tario plumbers perform and the recurring failure points in the region's pre-1990 housing stock. Last updated: 2026-07-02
Common questions
Isn't this what the home inspector does?
General inspectors do a visual pass — they don't camera the sewer, and many only note pipe material in passing. For older homes, a plumbing-specific evaluation is a different depth of look.
What's the single most expensive surprise?
A failed sewer lateral is the classic one — excavation and replacement runs well into five figures. That's why the camera inspection earns its fee on any pre-1980 purchase.
Can Tario do the evaluation during my contingency window?
Yes — call (410) 314-1161 with your timeline. We're open 24/7 for emergencies and schedule evaluations with contingency deadlines in mind.