10 Common Issues That Can Fail a Home Inspection

For both buyers and sellers, the home inspection can feel like the most stressful part of a real estate transaction. It’s the moment when a professional inspector examines the property from top to bottom, looking for potential problems that affect safety, structure, and livability. While no home is flawless, some issues consistently show up on inspection reports—and if they’re serious enough, they can derail a sale altogether.

By knowing the most common things that fail a home inspection, you can take proactive steps to address them before they become deal-breakers. Let’s look at the top ten problem areas in detail.

1. Roofing Problems

A home’s roof is its first line of defense against the elements. When it’s in poor condition, inspectors take note. Common issues include missing or cracked shingles, warped or curling materials, rusted flashing, and evidence of prior leaks. Sometimes the roof may simply be at the end of its lifespan, even if no major damage is present.

Why it matters: A damaged roof allows water intrusion, which can lead to mold, structural rot, and costly repairs inside the home. Replacing a roof can cost tens of thousands of dollars, so buyers often hesitate if problems are flagged.

How to prepare: Sellers should have their roof inspected and repaired before listing. Replacing damaged shingles, sealing flashing, or cleaning gutters can go a long way in avoiding inspection headaches.

2. Poor Drainage and Grading

Improper drainage is one of the biggest contributors to long-term foundation damage. If water collects near the base of a home, it can seep into the basement or crawl space and erode the soil supporting the foundation. Inspectors look for standing water, downspouts that dump water near the house, and negative grading where the yard slopes toward the home instead of away.

Why it matters: Excess water causes basement flooding, cracks in foundations, and creates the perfect environment for mold and mildew. These issues not only affect structural integrity but can also lead to health concerns.

How to prepare: Regrading soil, extending downspouts, or installing French drains are relatively affordable solutions that can prevent inspection failures in this category.

3. Electrical Hazards

Electrical issues are among the most serious red flags because of the risk of fire. Inspectors often find outdated wiring (like knob-and-tube or aluminum), double-tapped breakers, overloaded circuits, and ungrounded outlets. Older homes may have panels that no longer meet modern safety codes, such as Federal Pacific or Zinsco panels.

Why it matters: Electrical hazards aren’t just an inconvenience—they’re dangerous. Many buyers will walk away if extensive rewiring is needed, or they’ll demand major concessions.

How to prepare: Have a licensed electrician inspect the system, replace outdated panels, and add GFCI outlets near kitchens, bathrooms, and outdoor areas to meet code.

4. Plumbing Defects

Plumbing is another area where inspectors often find problems. Issues can range from small leaks under sinks to outdated materials like galvanized steel or polybutylene pipes. Poor water pressure, slow drains, and corroded pipes are also common. Inspectors will also check water heaters for age, functionality, and safety concerns like missing temperature-pressure relief valves.

Why it matters: Even minor leaks can cause hidden water damage, mold growth, and high utility bills. Replacing outdated piping throughout a house is a major expense.

How to prepare: Sellers should check for visible leaks, replace corroded fixtures, and ensure the water heater is up to code. Buyers should pay close attention to the type of piping and factor replacement costs into negotiations.

5. HVAC System Problems

Heating and cooling systems are critical for comfort and efficiency. Inspectors often flag HVAC units that are dirty, poorly maintained, or simply past their lifespan. A furnace or air conditioner that’s 15–20 years old may still be working, but it’s likely nearing replacement. Improperly sized or installed systems can also be flagged.

Why it matters: An inefficient or failing HVAC system leads to higher energy costs and uncomfortable living conditions. Replacing these systems can cost thousands, which makes buyers nervous.

How to prepare: Sellers should change filters, have units serviced, and provide maintenance records. Buyers should budget for eventual replacement if the system is old, even if it’s functioning at the time of inspection.

6. Foundation Cracks and Structural Concerns

Few inspection items worry buyers more than foundation issues. Inspectors look for visible cracks in walls or the foundation, uneven floors, sagging beams, or doors and windows that don’t open properly. Not all cracks are serious—many are cosmetic—but wide, horizontal, or expanding cracks can indicate significant structural problems.

Why it matters: Foundation repairs are among the most expensive home fixes, and some lenders may not approve financing until repairs are made. Buyers often see this as a deal-breaker unless the seller agrees to professional repairs.

How to prepare: Sellers should have any foundation cracks evaluated by a structural engineer before listing. Minor cracks can often be sealed, but major issues require professional attention.

7. Mold and Mildew

Mold thrives in damp environments, such as basements, crawl spaces, attics, or bathrooms with poor ventilation. Inspectors will look for visible mold, musty odors, or water stains that indicate potential growth.

Why it matters: Beyond being unsightly, mold poses potential health risks, especially to people with allergies or respiratory issues. Buyers often view mold as a sign of poor maintenance and hidden water problems.

How to prepare: Address the source of moisture first—fix leaks, improve ventilation, or install dehumidifiers. Professional mold remediation may be required for severe cases.

8. Pest Infestations

Termites, carpenter ants, rodents, and other pests can do serious hidden damage to a home. Inspectors may spot chewed wiring, damaged wood, droppings, or nests. In some states, a pest inspection is required before closing.

Why it matters: Pest damage can compromise structural integrity, and infestations can be difficult and expensive to eradicate. Buyers often require proof of treatment before moving forward.

How to prepare: Sellers should schedule routine pest control, seal entry points, and repair damaged wood. Buyers should ask for a pest inspection in addition to the general home inspection.

9. Attic and Insulation Issues

The attic often reveals hidden problems. Inspectors check for adequate insulation, proper ventilation, and signs of roof leaks. Poor insulation can make a home energy-inefficient, while inadequate ventilation leads to moisture buildup and potential mold growth.

Why it matters: Energy inefficiency drives up heating and cooling costs, while hidden roof leaks can cause extensive damage if left unchecked.

How to prepare: Adding insulation, installing attic fans or vents, and repairing leaks can help pass inspection. Sellers should also ensure attic access is clear so the inspector can evaluate it thoroughly.

10. Safety Concerns

Lastly, inspectors always look for general safety issues. These can include missing or nonfunctional smoke detectors, lack of carbon monoxide detectors, loose stair railings, trip hazards, and absence of GFCI outlets in kitchens and bathrooms.

Why it matters: While these items are often inexpensive to fix, they impact livability and lender approval. Many mortgage lenders require homes to meet basic safety standards before funding.

How to prepare: Sellers should install detectors, tighten railings, and check outlets before listing. These simple upgrades can make a big difference in passing inspection smoothly.

Final Thoughts

A home inspection doesn’t have to be a nightmare. Most issues—while common—are fixable, and many can be resolved before the inspection even takes place. For sellers, a pre-listing inspection is a smart move to uncover and address problems ahead of time. For buyers, knowing these common pitfalls can help you budget, negotiate, and enter a transaction with your eyes wide open.

By understanding what most often fails a home inspection, you’ll be better equipped to navigate the process confidently—whether you’re selling your home or preparing to buy your dream property.