The Seller Says the Mold Was Fixed. How to Check a Past Remediation Before You Buy

By John Calhoun, owner of Mold Remediation Gettysburg PA · Updated October 29, 2026

“We’re supposed to close next week, and the seller says the basement had mold but it was fixed.” A past mold problem isn’t a reason to walk away from a house. An unexplained one is. What you want to know is simple: where did the water come from, is that source fixed, what was removed, and how was the job proven done? A seller with a good answer usually has paperwork. If the paperwork is thin, the next step is checking the old problem area and its water source yourself, before your contract deadlines run out.

If the mold turned up during your home inspection rather than in the seller’s history, start with mold and the home inspection when buying instead. This page is about judging work someone already did. I’m not a lawyer, and nothing here is legal advice.

What good paperwork looks like

Pennsylvania doesn’t license mold remediators, as the PA mold license page explains, so there’s no state form to ask for. New York is a useful example of what thorough paperwork looks like, because its law requires it. New York’s Department of Labor says its mold law, which covers jobs over 10 square feet, requires an independent assessment to define the scope, prohibits the same person from doing both the assessment and the remediation on a property, and requires a post-remediation assessment, with a written clearance report at the end. Pennsylvania doesn’t require that, but it’s a good model to judge against.

The industry standard, ANSI/IICRC S520, now in its 2024 fourth edition, includes post-remediation verification as part of the job. Post-remediation verification explains what that check looks like, and what a mold inspection report should include helps you read whatever you’re handed. Contractors doing home improvement work in Pennsylvania generally register with the Attorney General, and you can look a company up on the Attorney General’s registration search.

What a home inspection does and doesn’t cover

Pennsylvania’s home inspection law defines a home inspection as a noninvasive visual examination, and it carves out examinations limited to air and water quality and environmental hazards. The two main inspector standards go further. ASHI says inspectors are not required to determine the presence of hazards including molds and mold-like substances, and InterNACHI excludes the presence of mold, mildew or fungus. A good inspector will still note a stain or a musty smell. They’re just not required to chase it.

The 2018 Superior Court case Medlock v. Chilmark Home Inspections shows why that matters. Five to seven months after closing, the buyers found wet, rotting wood behind an access panel, and their complaint alleged evidence of mold. The buyer testified the inspector hadn’t opened that panel.

Four places to check yourself

When a house has a mold history, I check the old problem area and then the places water usually comes from:

1. The repaired area itself. Moisture readings on the wall, floor or ceiling that was fixed. Dry is the whole point.
2. The source that caused it. If it was a roof leak, the roof and attic. If a sump, the sump and discharge. If a pipe, the pipe.
3. The rooms beside and below it. Water travels, and a fix on one side doesn’t always reach the other.
4. Anything new. Fresh paint, new drywall or a new floor in just one spot is worth a meter reading. New finishes can hide an old problem.

Old borough houses, newer township ones

Older homes have more history to account for. About 47.5% of borough homes predate 1940 in the Census estimates, while in Cumberland Township about 30% have gone up since 2000. A 1920s borough house may have had three generations of plumbing and roof repairs; a 2010s township house may have a tight envelope and oversized HVAC, which why brand-new houses get damp covers. The Gettysburg housing data page has the breakdown.

Before you close

Write down your contract deadlines, get the seller’s paperwork, and have the old problem area measured. Sellers’ side of the same transaction is in selling a house with mold in Pennsylvania.

This is John Calhoun at Mold Remediation Gettysburg PA. If you’re buying a house with a mold history, I’ll check the old work and the water source behind it, and tell you plainly what I find. See the list of mold services for what an inspection covers, or start with mold remediation in Gettysburg, PA.