What if the thing that stalls your closing isn't the buyer's financing, or a low appraisal, or a cold-feet moment three days out. What if it's something nobody was ever hired to look for.
That's the pattern I keep seeing in Upper St. Clair, and it has nothing to do with how well a house shows. A buyer's inspector walks the property, checks the roof, tests the outlets, runs the furnace, and writes up a clean report. Everyone exhales. Then, a week later, someone asks about the sewer line, or a radon test comes back at three times the federal action level, or a neighbor mentions the house used to have oil heat and nobody can say what happened to the tank. None of that was ever going to show up on the inspection everyone already paid for, because a standard visual inspection was never built to find it.
What A Standard Inspection Actually Covers
A general home inspection in Pennsylvania is a visual, non-invasive walkthrough of what's accessible: roof, foundation, electrical panel, plumbing fixtures, HVAC equipment, structure. It is thorough within that scope. It is also, by design, silent on a specific list of things:
- Radon gas, which requires its own separate test kit or monitor
- Buried oil tanks and other underground storage, which sit below what any inspector is contracted to dig for
- Sewer lateral lines, which require a camera fed into the pipe, not a walkthrough
- Septic systems, wells, and anything concealed inside walls or under slabs
None of these are oversights. They're excluded because they require different tools, different licenses, and a buyer or seller who thinks to ask for them. In a lot of markets that gap doesn't matter much, because the housing stock is young enough that none of these systems are old enough to fail yet. Upper St. Clair is not that market.
Three Systems, One Decade
The township's housing stock is overwhelmingly a product of one building era. Homes here were built mostly between the 1960s and the 1990s, with the heaviest concentration mid-century through the 1980s. That's not a cosmetic detail. It means the sewer laterals, the original heating infrastructure, and the below-grade conditions in thousands of Upper St. Clair basements are all the same age, give or take a decade, and they're all approaching the same end-of-useful-life window at roughly the same time.
You can see this play out at the municipal level, not just inside individual homes. In January 2025, crews began replacing aging gas lines along McLaughlin Run Road, working from the high school entrance to the Morrow Road intersection, with the project running into April. That's not a random capital project. It's the same underlying story as what shows up inside a 1970s colonial: infrastructure installed decades ago is reaching the point where replacement, not repair, is the realistic option. The township is dealing with it on Route 3004. Individual sellers are dealing with the residential version of it every time a house from that era goes under contract.
Radon: The Number Western Pennsylvania Homes Actually Post
Pennsylvania has one of the more serious radon profiles in the country. Statewide, roughly 40 percent of homes tested come back above the EPA's action guideline of 4 picocuries per liter, according to the state Department of Environmental Protection. The reason has to do with the ground underneath the region, not the homes themselves: old mine workings beneath the Pittsburgh area create pathways for the gas to migrate up through soil and foundation cracks regardless of how well a house was built or maintained.
Local test data reflects that. Readings collected from homes in the Upper St. Clair area put the average around 4.1 picocuries per liter, just over the action level, with individual results running far higher in specific basements. A short-term test kit costs about $20 to $30. If the result comes back above 4 pCi/L, the state recommends a second test to confirm, and if it holds, a mitigation system installed by a certified contractor, typically completed in under a day.
None of this is included in a standard inspection unless someone specifically requests it as an add-on. For a seller, that means a buyer's radon test can land after the inspection contingency has already been negotiated, sometimes after an offer has already been accepted on the assumption that inspection issues are settled.
The Line Nobody Sees Until the Camera Goes In
Older homes in this part of Allegheny County commonly run on clay or cast iron sewer laterals, the pipe connecting the house to the municipal line. Both materials are vulnerable to root intrusion and gradual deterioration over decades, and neither shows up in a standard inspection because the pipe is buried and inaccessible without a camera. A sewer scope is a separate, specialized service, and in a township where most of the housing stock predates 1990, it's a due-diligence step that experienced local buyers and their inspectors already know to request.
The problem for a seller is timing. If a buyer orders a sewer scope during their inspection period and it turns up root intrusion or a collapsed section, that's a five-figure repair conversation happening under contract, with a closing date already on the calendar and leverage tilted toward whoever asked the question first.
The Tank That Might Still Be There
Before natural gas infrastructure reached its current footprint across the township, plenty of homes here ran on oil heat. Many were converted over the decades that followed, but conversion didn't always mean the original tank came out of the ground. An underground tank that's been sitting unused for thirty or forty years can leak without any visible sign at the surface, and a leak is not something most homeowners insurance policies cover. According to guidance from the Eastern Pennsylvania Energy Association, buyers and sellers dealing with older housing stock are well advised to treat oil heat history as a real possibility until it's specifically ruled out, not an afterthought.
A standard inspection will not test for this. Locating a tank, confirmed or suspected, requires ground-penetrating radar or a dedicated scan, and it's a conversation that goes a lot better before a house is under contract than after a buyer's attorney raises it during the inspection period.
What Pennsylvania Law Actually Requires You To Say
Pennsylvania's Real Estate Seller Disclosure Law requires sellers to disclose known material defects to a buyer in writing before the agreement of sale is signed. The obligation covers what the seller actually knows. It does not require sellers to hire investigators or test for conditions they're genuinely unaware of, and Pennsylvania courts have kept that standard fairly strict. In Milliken v. Jacono, the state Supreme Court held that a material defect has to be something objectively real and quantifiable, not a subjective impression, which limits how far a disclosure claim can reach after closing.
Buyers, for their part, have up to two years after settlement to bring a claim if a seller knowingly withheld something they should have disclosed. That window is exactly why sellers benefit from finding these issues before listing rather than being surprised by them mid-transaction. A seller who never tested for radon and genuinely didn't know the level was elevated is in a very different legal position than one who tested, got a bad result, and said nothing.
The Sequence That Avoids The Renegotiation
For a seller in a home from this era, the order of operations that actually prevents a mid-contract surprise looks like this:
- Order a radon test early, well before listing, so a result above 4 pCi/L can be addressed or priced in rather than discovered by the buyer's inspector on a tight contingency clock.
- Ask whether the home ever had oil heat, and if the answer is unclear, have it checked before a buyer's attorney raises it as a condition of closing.
- Have the sewer lateral scoped, particularly if the home has never had one done, since root intrusion in a fifty-year-old clay line is common enough in this area to be worth ruling out rather than hoping it doesn't come up.
None of these are expensive relative to what they prevent. All three are more useful to a seller done on their own schedule than discovered on a buyer's.
FAQ
Do I have to disclose a radon problem if I never tested for it? No. Pennsylvania's disclosure law only requires you to disclose what you actually know. If you never tested, you have nothing to disclose on that point, though testing before you list still protects you from a worse surprise later.
Is a sewer scope legally required before selling? No. It's not a legal requirement anywhere in Pennsylvania. It's a practical one in a township where most homes are old enough that the lateral is a genuine question mark, and buyers here increasingly ask for one anyway.
What happens if I find an oil tank I didn't know was there? Once you know, you know, and that knowledge becomes something you're required to disclose going forward. That's exactly why it's worth checking before you list rather than after a buyer's inspector or attorney raises it during a contract you're already trying to close.
If you're getting ready to list a home in Upper St. Clair and want to walk through what your specific property might be dealing with before a buyer's inspector finds it first, Theresa Doran is happy to help you build that plan. Schedule a free consultation and let's get ahead of it together.
