What Does a Home Inspector Not Check Before You Buy a House?

By Aubre J. Stacknick, Global Real Estate Advisor, Piatt Sotheby's International Realty. Originally published on aubrestacknick.com.

A general home inspection is a visual look at what can be seen and reached on the day. It does not open walls, see buried pipes, test for radon or mold, or judge code compliance. Know the gaps before you rely on the report.

Buyers treat the inspection report as a clean bill of health. It is a snapshot of the visible, accessible parts of a house, written by a person with a flashlight and a ladder and a few hours.

That is valuable, and it has limits. The limits are where expensive surprises hide.

Aubre J. Stacknick is a Global Real Estate Advisor with Piatt Sotheby's International Realty in Pittsburgh, PA, helping buyers and sellers across Western Pennsylvania see a home through a builder's eyes. I read inspection reports for a living, and I read what is missing as carefully as what is there.

What does a home inspection actually cover?

A general inspection looks at the major visible systems and structure: roof surface, exterior, foundation where it can be seen, attic and basement, plumbing and electrical that are exposed, heating and cooling, and the condition of windows, doors, and interior finishes.

It is typically visual and non-invasive. The inspector does not take things apart. Most follow written standards of practice that define what is and is not included, and a good inspector will give you that list. Ask for it before you hire.

What can a general inspector not see?

Anything hidden. A report cannot describe what is behind a wall, under a floor, or under the ground.

• Inside walls and ceilings. Wiring, plumbing, insulation, and framing behind finished surfaces are out of sight. The inspector reads the surface and the signs.
• Underground pipes. The sewer line and any buried supply line, oil tank, or drain are not visible. A sewer scope is a separate camera inspection.
• Under the roof surface. Many inspectors do not walk every roof, and none can see the deck under the shingles.
• Inside the chimney. A visual look at the firebox and cap is not the same as a camera inspection of the flue. Fire safety is a reason to ask for the deeper check.
• Behind furniture, stored items, and fresh finishes. Water stains can be hidden by paint, and a damp corner by a couch.

What is usually left out on purpose?

Several things are commonly outside a general inspection, and they are the ones that cost money or health.

• Radon. Testing is a separate service. The EPA says testing is the only way to know the radon level in a particular house.
• Mold. An inspector may note moisture and visible growth but does not usually sample or lab test.
• Pests. Wood-destroying insects are often a separate inspection.
• Lead paint, asbestos, and other hazardous materials in older houses. These need specialists.
• Code compliance and permits. An inspector reports condition, not whether work was permitted or built to code. That is a records question for the township.
• Septic systems and wells. These need their own inspections and water tests.
• Pools, outbuildings, and sprinkler systems. Often excluded or limited.
• Cosmetic items and the future. The report will not tell you how long a roof or water heater will last.

Which specialists are worth adding?

Match the extra inspection to what the house shows, not to a checklist.

• A sewer scope for older houses or houses with mature trees.
• A radon test, which is a separate service.
• A structural engineer if you see cracking, bowing, or removed walls.
• A licensed electrician if the panel or wiring is old or partly updated.
• A chimney inspection if you plan to use the fireplace.
• A roofer if the roof age is unknown or the attic shows staining.
• A pest inspection if you see damage or the lender requires it.

For how this works on a renovated house, read How Can You Tell If a Renovation Was Done Right Before You Buy?. For the sewer line in particular, read What Does a Sewer Scope Find, and Is It Worth It on an Older Pittsburgh House?.

Should you attend the inspection?

Yes. Go for the last hour, or the whole thing if you can. The inspector will show you things that never make the report, like where the shutoffs are and what normal wear looks like. Ask what they could not see and why. That list is worth more than the summary page.

How should you read the report?

Sort it into three piles and ignore the rest.

• Safety and structure. Anything that affects people or the frame of the house.
• Water. Roof leaks, drainage, and moisture, because water causes the largest repair bills.
• Big mechanicals near the end of life. Furnace, water heater, roof, and electrical panel.

Cosmetic notes and small maintenance items are normal in any house. They are not reasons to walk away. For how I tell small from large, read How Can I Tell if a House Has Expensive Problems Before I Buy It?.

What should you do about the limits?

Treat the limits as questions for the seller and the specialists. Ask the seller about the roof, the sewer line, past water, and permitted work. Read the property disclosure. Then decide which limits matter for this house and add the inspection that closes each one.

The common mistakes buyers make with inspections

• Treating the report as a guarantee
• Skipping the sewer scope and radon test to save a little
• Not reading the inspector's own limits and exclusions
• Missing the inspection, then reading the summary only
• Waiving the inspection to win a bid without knowing what is at risk

Common questions

If you want a builder's second read on an inspection report before you decide, book a 30-minute call. Bring the report.