How do you know if the pipe running from your foundation to the street is fifty years old and starting to fail? You don't, not from a standard home inspection, and not from looking at the house. The lawn is mowed, the brick is clean, the kitchen was redone in 2019. None of that tells you what's six feet underground.
That gap matters more in Troy than in a lot of Metro Detroit suburbs, because Troy's sewer lines were not all laid at the same time or with the same material. Some of the city's housing stock sits on pipe installed before most of today's buyers were born. Some sits on lines that are barely older than the roof. Which side of that split a given house falls on has less to do with how the property looks and more to do with when its subdivision was platted.
What Every Troy Inspection Skips
A standard Michigan home inspection, the kind built around ASHI (American Society of Home Inspectors) protocols, looks at the roof, the foundation, the electrical panel, the furnace, and the visible plumbing inside the walls. It does not look underground. The sewer lateral, the pipe that carries wastewater from your house to the city main, sits outside the inspector's scope entirely.
That's not a shortcut or an oversight. It's simply outside what a general inspection is designed to catch. Seeing the inside of that pipe requires a separate service, a sewer scope, where a plumber feeds a waterproof camera through a cleanout and records what's actually down there. Most sewer scopes run somewhere between $100 and $500 depending on the length of the line and how easy the cleanout is to reach. Compared to what a bad line costs to fix, that's a small number to skip.
How Troy Ended Up With Two Different Sewer Systems
Troy incorporated as a city in 1955, largely to keep Clawson, Royal Oak, and Birmingham from annexing its farmland first. What happened next was fast. The city's population nearly doubled during the 1950s, then nearly doubled again by 1970, jumping from about 19,400 residents in 1960 to just over 39,400 by the end of that decade. Subdivisions replaced farmland north of Big Beaver Road through this stretch, and the city's water and sewer systems had to keep pace: more than 100 miles of sanitary sewer were in the ground by 1967 alone, built to serve a wave of new housing tracts arriving faster than almost anywhere else in the state that decade.
That construction boom is exactly why a lot of Troy's older neighborhoods carry clay tile or Orangeburg sewer laterals today. Both materials were standard for residential construction through the 1960s and into the early 1970s, and both have a finite service life that's now largely spent. Newer sections of the city, including later development corridors around Rochester Road, went in after plastic pipe became the industry norm, so those lines are working with a different clock entirely.
Local plumbers see this split every day. Triton Plumbing, based in Troy and serving Oakland and Macomb counties, notes that homes built between the 1960s and 1980s across the region are especially likely to still be running on aging cast iron or clay lines that need attention. Another Troy-focused plumbing service makes the same distinction even more directly, drawing a line between the city's older pockets near Big Beaver Road, where original clay pipe is common, and its newer developments toward Rochester Road, where the lines are considerably younger. Neither company is describing a hypothetical. They're describing what they find when they run a camera down a Troy sewer line, street by street.
What's Actually Under Your Yard
The material matters because each one fails on a different timeline.
| Material | Common installation era | Typical lifespan | What tends to go wrong |
|---|---|---|---|
| Orangeburg (tar paper fiber) | 1950s to early 1970s | About 50 years | Delaminates, flattens, collapses under soil pressure |
| Clay tile | Pre-1970 | 50 to 75 years | Joints separate, roots intrude at every seam |
| Cast iron | 1900s to 1980 | 50 to 80 years | Interior corrosion eventually perforates the pipe wall |
| PVC (modern) | 1970s onward | 100+ years | Rare early installations used inferior grades |
A house built in Troy in the early 1970s and still running its original lateral is, by these numbers, sitting on a pipe that has already reached or passed the upper end of its expected life. That's not a reason to panic about any specific address. It's a reason to actually look, rather than assume the pipe is fine because the house looks fine.
What the Camera Costs, and What It Finds
The scope itself is cheap. What it sometimes reveals is not. Repair estimates cited across plumbing and inspection sources for problems commonly found in older Michigan sewer lines fall into a few rough tiers:
- Root intrusion requiring cleaning: a few hundred dollars, often handled with jetting before closing
- Cracked or offset clay tile: several thousand dollars, a real negotiation line item
- Full replacement of a failing Orangeburg or badly deteriorated clay line: typically somewhere between $5,000 and $25,000 depending on length, depth, and whether trenchless methods are an option
Trenchless repair, where a new pipe is pulled through the old one without digging up the yard, has become common across the region and can cost less overall than full excavation once landscaping and driveway restoration are factored in. Whether it's an option depends on what the camera shows, not on how motivated anyone is to avoid a trench.
The Three Ways This Gets Negotiated
When a sewer scope turns up a problem during a Michigan purchase, buyers generally have three paths, and the right one depends on the severity of what the camera found.
- Ask for the repair before closing. This works for smaller issues, a section of root intrusion or a localized crack, where a licensed plumber can fix the specific defect on a defined timeline.
- Negotiate a closing credit. This gives the buyer control over the contractor and timing after closing, which matters when the fix is bigger than a quick patch. Loan programs can limit how credits are structured, so this is worth confirming with a lender before it becomes the plan.
- Renegotiate the price. This spreads the cost over the life of the loan rather than putting money back at closing, and tends to make more sense when the buyer already has cash reserved for the work.
Michigan purchase agreements are not uniform on how inspection contingencies are worded, so the practical outcome depends on the specific contract, the deadline for a seller's response, and what happens if the two sides don't reach an agreement in time. That's a conversation to have with your agent before the offer goes in, not after the camera comes back with bad news.
What This Means If You're Buying in Troy
If you're touring homes near Big Beaver Road, or anywhere in a subdivision that was platted before the mid-1970s, build a sewer scope into your inspection period regardless of how the house shows. Ask the listing agent or seller what decade the subdivision went in. If nobody knows offhand, the city's own property records are public and searchable, and confirming a build year takes a few minutes.
If you're looking at newer construction closer to Rochester Road or in one of Troy's more recently developed pockets, the risk profile is genuinely different. That doesn't mean skip the scope. It means the conversation with your plumber will likely be shorter.
What This Means If You're Selling an Older Troy Home
A pre-listing sewer scope costs about the same as the one your buyer will eventually order anyway. Getting ahead of it means you're not negotiating from a defensive position when the buyer's inspector calls with news, and it gives you the option to handle a smaller issue on your own schedule rather than a buyer's.
A Few Questions We Hear Often
Does my homeowners insurance cover sewer line failure? Typically not for normal wear, age-related corrosion, or root intrusion. Most policies treat this as a maintenance issue rather than a covered loss, so it's worth confirming with your carrier rather than assuming.
Can I skip the sewer scope if the house passed a regular inspection? You can, but a standard inspection was never looking underground in the first place, so a clean report doesn't tell you anything about the lateral.
Is a sewer scope worth it on new construction? Often yes. Construction debris and installation damage can affect even a brand new line, though the failure modes are different from a 1965 clay pipe.
If you're weighing a purchase near Big Beaver Road, comparing an older Troy neighborhood against something newer, or getting ready to list a home built during the city's 1960s boom, it helps to have someone who can walk the specifics with you before the offer goes in or the sign goes up. Kim Nagy and the team have spent decades in these Troy neighborhoods and can help you figure out what questions to ask before the inspection period starts, not after.
