The Limits of a Visual Inspection
Home inspections are visual and non-invasive. That's the industry standard, set by organizations like ASHI and InterNACHI. Inspectors look at what they can see without moving furniture, cutting into walls, or dismantling components.
This means everything behind finished surfaces is invisible. Walls, ceilings, floors, cabinets, insulation. If something's covered up, the inspector can't see it.
Ted's basement had finished walls. Painted drywall, trim, the works. The inspector saw a nice-looking finished basement. What he couldn't see was the nightmare behind it.
What "Non-Invasive" Really Means
Inspectors don't move heavy furniture. They don't lift carpets. They don't remove access panels that are screwed shut. They don't dig around landscaping. They don't crawl into spaces smaller than their bodies.
There's a good reason for this. The house doesn't belong to the buyer yet. The inspector has no right to alter, damage, or disturb the property. Even moving a couch could create liability issues.
But that means areas are hidden. Carpeting can cover water stains. Furniture can hide wall damage. Landscaping can obscure foundation problems. These limitations are built into the inspection process.
Behind the Walls
Ted's mold was behind finished drywall. But that's not the only thing hiding in wall cavities.
Electrical wiring runs through walls. An inspector can evaluate outlets and the panel, but not the wiring itself. If someone did DIY electrical work 15 years ago, connecting wires incorrectly inside the wall, an inspection won't catch it.
Plumbing runs through walls. A slow leak inside a wall cavity might not show exterior signs for years. The inspector tests water pressure and looks for visible leaks, but hidden pipes are hidden.
Insulation varies behind walls. That energy-efficient house might have gaps in insulation that don't show up during a visual inspection. Only thermal imaging or opening walls reveals the truth.
When Previous Owners Hide Things
This is what happened to Ted. Whoever owned the house before him knew about the water problem. Instead of fixing it properly, they covered it up. Fresh drywall, paint, done.
An inspector can't detect deception. If someone deliberately conceals a problem, a standard inspection won't find it. That's not the inspector's failure. It's a fundamental limitation of what inspection can accomplish.
Ted eventually tracked down the previous owner through property records. The guy had disclosed "minor basement moisture in past, since repaired." Technically true in the narrowest sense. Ethically bankrupt.
Under the House
Crawlspaces get inspected when accessible. But "accessible" has limits. A crawlspace with 18 inches of clearance isn't getting a full inspection. Neither is one filled with stored items, or one without proper lighting, or one with standing water.
My friend Rosa's inspection noted "crawlspace inspection limited due to low clearance." She didn't think much of it at the time. Eight months later, she found extensive termite damage in the area the inspector couldn't reach.
Slab foundations present different challenges. Everything is under concrete. Plumbing runs through or under the slab. If a pipe fails, you might not know until water appears somewhere it shouldn't.
Underground Systems
Sewer lines, septic systems, and underground drainage typically require specialized inspections beyond the standard home inspection.
A colleague of mine, Karen, skipped the sewer scope inspection to save $200. Two months after closing, her main sewer line collapsed. Root intrusion had been destroying the clay pipes for years. The replacement cost $11,800.
"The inspector can't see underground," she told me. "I should have spent the $200."
Standard inspections don't include sewer scopes, septic evaluations, or underground tank detection. If you want to know about underground systems, you need to pay for those inspections separately.
What Specialized Inspections Cover
A sewer scope sends a camera through your main line to check for cracks, root intrusion, bellies, and blockages. Cost: typically $125-250.
A septic inspection evaluates tank condition, drain field function, and system adequacy. Cost: typically $300-500.
Underground storage tank sweeps detect buried oil tanks that could be leaking. Cost: typically $100-200 for initial scan.
None of these are included in a standard home inspection. All of them can save you from five-figure surprises.
Timing Problems
A home inspection is a snapshot. It captures conditions at one moment in time, during a 2-4 hour window.
Problems that come and go might not appear during that window. A roof that leaks only in heavy rain won't leak during your sunny Tuesday afternoon inspection. A furnace that struggles in extreme cold might perform fine on a mild fall day.
Seasonal Issues
Buy a house in summer, and you won't know how the heating system handles a cold snap. Buy in winter, and the AC unit doesn't get tested under real conditions.
Inspectors test systems when possible, but testing isn't the same as months of actual use. A system that runs fine for 20 minutes during an inspection might fail after running all day.
Intermittent Failures
My water heater worked perfectly during inspection. Three weeks after moving in, it started tripping its thermal cutoff randomly. The problem was an aging thermostat that failed intermittently.
The inspector tested the water heater. Hot water came out. System worked. But intermittent problems don't announce themselves on demand.
The Disclosure Gap
Sellers are legally required to disclose known problems in most states. But "known" does a lot of heavy lifting in that sentence.
Some sellers genuinely don't know about issues. They lived with that musty basement smell for years and never investigated. To them, it's just how the house smells.
Other sellers know exactly what's wrong and choose not to disclose. They're gambling that buyers won't discover problems until after closing. It's unethical, sometimes illegal, but it happens.
Ted's situation was the second kind. The previous owner knew about the mold. Chose to hide it. Hoped Ted wouldn't find out. Ted had no way to detect this during the buying process because the concealment was deliberate and thorough.
What You Can Do
Knowing inspections have limits doesn't mean they're useless. It means you should supplement them intelligently.
Add Specialized Inspections
For older homes: add a sewer scope. The $200 could save you $12,000.
For homes with septic systems: get a septic inspection. Always.
If you suspect mold or have any allergy concerns: consider air quality testing.
For homes with known or suspected foundation issues: hire a structural engineer.
Ask Questions
Ask the seller directly about past water intrusion, repairs, insurance claims, and known issues. Some problems come out in conversation that never made it to disclosure forms.
Ask the neighbors. They often know more about the house's history than anyone. That's how Ted eventually pieced together what had happened. His neighbor remembered water trucks in the driveway three years before.
Read the Report Carefully
When the inspector writes "limited inspection due to...," take that seriously. Those limitations aren't disclaimers to ignore. They're telling you what they couldn't evaluate.
Consider getting a second opinion or specialized inspection for areas that were inaccessible or limited.
Living With Uncertainty
Ted sued the previous owner eventually. Settled for a fraction of his repair costs. It took 14 months and a lot of stress.
He still lives in the house. Fixed the mold problem, replaced the framing, installed proper drainage. The house is better now than it was when he bought it, ironically.
"I know every inch of these walls now," he told me last year. "That's something."
Home inspections catch a lot. But they can't catch everything. Understanding their limits helps you prepare, ask better questions, and add the right specialized inspections. It won't eliminate all risk. Nothing can. But it tilts the odds in your favor.