This post was expanded and updated in March, 2026.
A plumbing inspection in an older U.P. home should check for more than drips and leaks. Here in the Upper Peninsula, we inspect a lot of older homes. Properties in Marquette County, Delta County, Alger County, and across the U.P. that have great bones, real character, and plumbing systems that were installed before your parents were born.
Some of it is still holding up well. Some of it is quietly waiting to cause a problem.
The plumbing system is one of the most vital components of a house. Even minor plumbing issues can disorganize your day and disrupt your daily routine. Discovering plumbing issues before they get out of hand can save you the money and hassle of a faulty plumbing system.
The five most common issues we find — galvanized pipes, backflow risks, unventilated S-traps, ungrounded plumbing, and missing sewer clean-outs — can range from an inconvenience to a genuine safety hazard. Here’s what they are, why they matter, and what to do about them.
Most people assume their plumbing is fine as long as the water runs. That’s reasonable — until it isn’t.
As a Certified Master Inspector® with 1,500+ completed inspections across the U.P., Rich has seen just about every plumbing inspection issue there is — from the kind that shows up as a stain on the ceiling to the kind that turns into an emergency.
We inspect the plumbing system on every property we service, following InterNACHI’s Standards of Practice for plumbing. Our job isn’t just to tell you the water runs. It’s to tell you if the system is safe and how much life it has left. This guide covers five red flags we look for on every inspection, and what they mean for you as a buyer or homeowner.
What Are the Biggest Plumbing Red Flags in an Older Home?
In U.P. homes built before 1980, the five plumbing issues we find most often are aging galvanized pipes, backflow risks at outdoor hose bibs, unventilated S-traps, ungrounded or unbonded plumbing, and the absence of a sewer clean-out. Each one ranges from a manageable repair to a legitimate safety concern — and most are invisible without a trained eye.
1. Galvanized Pipes: The Clock Is Ticking
If you’re buying an older home in Negaunee, Ishpeming, Escanaba, Munising, or anywhere else in the U.P. with significant pre-1970s housing stock, there’s a solid chance the home has galvanized steel pipes.
Galvanized pipes were the standard for decades. They’re steel pipes coated with a layer of zinc to slow corrosion. The problem is that coating doesn’t last forever — and in Michigan’s climate, with its hard water and freeze-thaw cycles, galvanized pipes age faster than they might elsewhere.
Two things happen as they get old:
Mineral buildup inside the pipe. Over time, minerals deposit on the inner walls, slowly shrinking the inside diameter. In mild cases, you notice reduced water pressure. In severe cases, flow drops to a trickle.
Corrosion at the threaded joints. When galvanized pipe is cut to thread the fittings, the protective zinc coating is cut away, leaving bare metal exposed. Those threaded joints are where corrosion sets in first — and eventually, where it fails.
Galvanized piping has a typical service life of around 50 years. If the home has surpassed that mark, budget for replacement. Not necessarily this year, but in the not-too-distant future. A licensed plumber can assess current condition and help you prioritize.
Watch for: Reduced water pressure, rusty or discolored water, visible rust or white mineral deposits on exposed pipes.
2. Backflow & Cross-Connections: How Clean Water Gets Dirty
This one surprises people. Your municipal water supply is pressurized, which is what pushes water out of your tap. Under normal conditions, that pressure keeps contaminated water from flowing backward into the supply lines.
But pressure isn’t always normal. A water main break, a sudden surge in demand, or a pump failure can cause a temporary pressure drop — and when pressure drops, water can flow the wrong way. That’s called backflow, and it can pull contaminated water into your clean supply lines.
The most common source in residential homes? The outdoor hose spigot.
Picture this: you’ve got a garden hose submerged in a bucket of soapy water while you wash the car. The phone rings, you go inside, and at that moment the city is doing work on the main and pressure drops. That soapy water can siphon right back into your home’s supply.
It sounds unlikely. It happens more than you’d think.
The fix is cheap and simple: a vacuum breaker on every outdoor hose bib. They cost about $10 at any hardware store and thread right onto the spigot. If your home doesn’t have them, it’s one of the easiest wins on this list.
As a homeowner, it’s worth knowing to look for:
- Vacuum breakers on all outdoor hose bibs— a $10 fix that’s easy to add yourself
- Proper air gaps at appliances like dishwashers— a small but important detail that prevents drain water from siphoning back into the supply
- Backflow preventers on irrigation systems and any connection between potable and non-potable water sources
3. S-Traps: The Drain Issue That Lets Sewer Gas In
S-traps show up in about 80% of older U.P. homes we inspect, and they’re one of the more straightforward issues we flag in a plumbing inspection.
Here’s the short version: drain traps hold a small amount of water that acts as a seal against sewer gases. An S-trap is shaped like an “S,” and the problem is that without proper venting, the weight of draining water can siphon that protective barrier right out of the trap. The seal can also dry out in a drain that sees little use, or get wicked away slowly by hair or debris caught in the trap.
Sewer gases smell bad. More importantly, some of them are harmful in enclosed spaces.
That said, it’s worth keeping this in perspective: many S-traps go decades without causing a single problem. It’s not a defect that demands immediate action — it’s a design limitation to be aware of. If you’re not experiencing any gurgling or odor, you may never have an issue. But if the gurgling starts, it’s time to address it.
You have two good options:
- The thorough fix is swapping the S-trap for a P-trap — a more reliable design that holds its seal under normal conditions.
- The quicker and cheaper option is installing an air admittance valve (AAV), sometimes called a burpee valve. An AAV solves the venting problem that makes S-traps fail in the first place, costs very little, and is something most homeowners can tackle on their own (with perhaps a little help from a 14-year-old on YouTube).
Either fix is acceptable — we won’t flag a properly installed AAV on a plumbing inspection report.
How to tell if you have one: Look at the trap. If it is shaped like an S, you have an S trap. (Keep in mind that sometimes they’re twisted and don’t look like an S from your angle, so you’ll need to follow the curves with your eyes.) For a quick check on whether yours has an issue, flush the toilet and watch whether the nearby sink gurgles. Gurgling often points to an S-trap or a venting issue.
4. Ungrounded or Unbonded Plumbing: Where Electrical Meets Plumbing
This one belongs in both the plumbing and the electrical sections of an inspection report.
Metal pipes are conductors. In homes where the electrical system isn’t properly grounded — or where the plumbing isn’t bonded to the grounding system — a fault in the wiring can energize the pipes. That means someone turning on a faucet could complete a circuit.
It’s a real hazard in older homes with mixed-generation wiring, and it’s not always obvious without a proper inspection. A correctly installed grounding and bonding system directs stray current safely to ground before it can travel through the pipes.
If your home has older wiring, this is one of the reasons a thorough plumbing inspection matters — not just a walk-through.
5. No Sewer Clean-Out: A Small Omission With Big Consequences
A sewer clean-out is a capped pipe that gives a plumber direct access to your lateral sewer line — the pipe that connects your home’s drain system to the septic tank or municipal sewer. Without it, clearing a blockage means working through a drain opening or, in some cases, digging up the line entirely.
In most of the country, that’s an inconvenience. In the Upper Peninsula, it’s a potential disaster.
If you don’t have a clean-out and your sewer line backs up, there’s a good chance the fix will require excavation. And if you’re a Yooper, you already know how this story ends: the blockage will happen in January, it will be 20 below, and there will be three feet of snow and ice sitting on top of your sewer lines. We’ve seen it happen.
A clean-out is a relatively modest addition if you’re already doing plumbing work. If your home doesn’t have one, it’s worth discussing with a licensed plumber — before winter, ideally.
What Happens During a Plumbing Inspection?
To be clear: we don’t offer stand-alone plumbing inspections. What we do is inspect the plumbing system as a core part of every standard home inspection we perform, following InterNACHI’s Standards of Practice for plumbing inspection.
That means we’re evaluating:
- All visible supply and drain lines
- Water heater condition, age, and settings
- Fixture function and flow
- Drain traps and venting
- Exterior hose bibs and vacuum breakers
- Sewer clean-out access
- Grounding and bonding of metal piping
- Evidence of past leaks or active moisture
We’re not going to run a camera through the sewer line or pressure-test the supply system — that’s beyond the scope of a standard home inspection. But we will give you a clear, honest picture of what’s there, what’s aging, and what needs attention.
Ready to Know What You’re Buying?
Whether you’re buying a vintage Marquette craftsman, a farmhouse in Menominee County, or a camp up in Alger County, U.P. Home Inspection, LLC is here to give you the full picture — plumbing inspection included.
We’re Michigan’s Upper Peninsula home inspection company, and we know these homes. Our inspectors are trained to spot the issues that matter, report them straight, and help you make a confident decision about your investment.
Schedule your home inspection today.
Or call us directly at (906) 360-3879.
U.P. Home Inspection, LLC | Eben Junction, MI | Serving Marquette, Alger, Delta, Schoolcraft, Dickinson, and Menominee counties
Rich Beasley leads U.P. Home Inspection, LLC as a Certified Master Inspector® with deep roots in Upper Peninsula construction needs. In 2025, Rich earned the prestigious CMI® designation from the Master Inspector Certification Board, reflecting our team’s dedication to experience, education, and the highest industry standards.