Technically, nothing "fails" a home inspection. A home inspection is not a pass/fail test. Inspectors document the condition of the home's systems and components — they report what they find and let the buyer decide how to proceed. There is no score, no grade, and no official failure.

That said, certain findings routinely cause buyers to renegotiate, request repairs, or walk away from a deal entirely. After performing over 5,000 inspections across Tennessee since 2014, the team at Insight Home Inspection Services has seen the same categories of serious issues come up again and again. Here are the most common ones.

Foundation and Structural Problems

Foundation issues are the findings that alarm buyers more than anything else, and for good reason. The foundation holds up the entire house. Signs of foundation problems include:

  • Horizontal cracks in block or poured concrete walls (especially if bowing inward)
  • Stair-step cracking in brick or block
  • Significant settling or shifting visible as uneven floors, sticking doors, or cracked drywall
  • Water intrusion through foundation walls or floor
  • Deteriorated or undersized structural supports in crawl spaces
  • Sagging floor joists or beams

Tennessee's clay-heavy soils expand when wet and contract when dry, creating constant pressure on foundations. This makes foundation movement common, particularly in homes without proper drainage and grading.

What inspectors look for: Crack patterns (horizontal vs. vertical vs. diagonal), evidence of previous repair, moisture staining, efflorescence (white mineral deposits indicating water movement), and the relationship between exterior grading and foundation performance.

Typical repair costs: Minor crack sealing starts around $500-$1,500. Significant foundation repair involving helical piers, wall anchors, or underpinning ranges from $5,000 to $30,000+. Full foundation replacement is rare but can exceed $50,000.

Roof Damage and Failure

A roof nearing or past the end of its useful life is one of the most common findings that changes the trajectory of a deal. Buyers are reluctant to inherit a $10,000-$20,000 replacement within the first few years of ownership.

Inspectors look for:

  • Missing, curling, cracked, or granule-depleted shingles
  • Damaged or improperly installed flashing around chimneys, vents, and valleys
  • Active leaks or evidence of past leaks (staining on decking visible from the attic)
  • Sagging or uneven roof planes indicating structural issues with the decking or framing
  • Multiple layers of shingles (Tennessee code limits the number of layers)
  • Damaged or missing ridge caps and boot covers around pipe penetrations

Tennessee's thunderstorms, high winds, and occasional hail make roof damage common. Homes in Nashville, Knoxville, and Chattanooga are all in regions that experience severe weather regularly.

Typical repair costs: Spot repairs and flashing fixes range from $300 to $1,500. A full roof replacement on a typical Tennessee home costs $8,000 to $20,000+ depending on size, pitch, material, and the number of layers to remove.

HVAC System Failure or End of Life

Heating and cooling are not negotiable in Tennessee. Summers are hot and humid; winters are cold enough to freeze pipes. An HVAC system at or beyond its expected lifespan is a major negotiation point.

Inspectors evaluate:

  • Age of the furnace/heat pump and air conditioning condenser (most systems last 15-20 years)
  • Operational performance — does the system heat and cool effectively?
  • Condition of the evaporator and condenser coils
  • Ductwork connections and insulation
  • Safety concerns: cracked heat exchangers (fire and carbon monoxide risk), improper gas connections, missing flue pipes
  • Refrigerant line condition
  • Thermostat function

Typical repair costs: Minor HVAC repairs run $200-$1,500. A full system replacement (furnace/heat pump + air conditioner + coil) typically costs $5,000 to $15,000 depending on the system type, efficiency rating, and home size.

Electrical Hazards

Electrical deficiencies are safety-critical and can affect a buyer's ability to insure the home. The most concerning electrical findings include:

  • Federal Pacific (FPE) Stab-Lok or Zinsco panels: These panels have documented failure rates and many insurance companies will not write a policy until they are replaced.
  • Aluminum branch wiring: Common in homes built in the mid-1960s to mid-1970s, aluminum wiring has a higher fire risk at connection points and may require remediation.
  • Double-tapped breakers: Two wires connected to a single breaker terminal (unless the breaker is rated for it) creates a loose connection and fire risk.
  • Ungrounded outlets and missing GFCI protection: Outlets in kitchens, bathrooms, garages, exteriors, and near water sources should have ground-fault protection.
  • Exposed or improper wiring: Open junction boxes, amateur wiring, knob-and-tube wiring still in service, and extension cords used as permanent wiring.
  • Undersized service: A home with 60-amp service may not support modern electrical demands and will need a service upgrade.

Typical repair costs: Panel replacement runs $2,000 to $4,000. Aluminum wiring remediation (COPALUM or AlumiConn connections) costs $3,000 to $8,000+ depending on the number of connections. A full service upgrade from 100-amp to 200-amp typically costs $2,000 to $3,500.

Plumbing Problems

Plumbing findings range from minor fixture issues to system-wide concerns that require significant investment.

  • Polybutylene piping: Widely installed in Tennessee homes from the late 1970s through the mid-1990s, polybutylene (poly-B) supply lines are prone to sudden, catastrophic failure. Many insurance companies require replacement or will not insure the home.
  • Galvanized steel pipes: Found in older homes, galvanized pipes corrode from the inside out, reducing water pressure and eventually developing leaks.
  • Active leaks: Under sinks, at water heater connections, at supply valves, and at hose bibs.
  • Water heater issues: Age (most last 8-12 years), corrosion, missing safety features (temperature/pressure relief valve, proper discharge pipe, seismic strapping in some jurisdictions), and signs of leaking.
  • Sewer line problems: Root intrusion, bellies, cracks, and deteriorated clay or cast iron pipes identified during a sewer scope inspection are common in older Tennessee homes.
  • Functional drainage problems: Slow drains, improper venting, and cross-connections.

Typical repair costs: Water heater replacement costs $1,200 to $3,000. A full re-pipe of a home (replacing polybutylene or galvanized with PEX or copper) costs $4,000 to $15,000. Sewer line replacement runs $3,000 to $10,000.

Water Damage, Mold, and Moisture Issues

Water damage is frequently the root cause of multiple other problems. Inspectors look for:

  • Staining on ceilings, walls, and around windows indicating active or past leaks
  • Musty odors suggesting hidden moisture or mold growth
  • Visible mold on surfaces in attics, crawl spaces, basements, and bathrooms
  • Deteriorated or missing vapor barriers in crawl spaces
  • Condensation on windows, ductwork, or pipes indicating humidity problems
  • Water intrusion in basements through walls or floor cracks

Tennessee's high humidity, heavy rainfall, and clay soils create persistent moisture challenges. Crawl spaces are particularly vulnerable — a crawl space without a properly sealed vapor barrier and adequate ventilation (or encapsulation) will develop moisture problems over time.

Typical repair costs: Mold remediation ranges from $1,500 to $10,000+ depending on scope. Crawl space encapsulation costs $5,000 to $15,000. Water damage repair varies enormously depending on extent and location.

Termite and Wood-Destroying Insect Damage

Tennessee's warm, humid climate is ideal for subterranean termites, which are active in all 95 counties. A wood-destroying insect (WDI) inspection is a common ancillary service added to home inspections.

Inspectors and pest professionals look for:

  • Mud tubes on foundation walls (the telltale sign of subterranean termites)
  • Damaged or hollow-sounding wood in structural members
  • Frass (sawdust-like droppings from carpenter ants or drywood termites)
  • Carpenter bee bore holes in fascia and trim
  • Previous treatment evidence (drill holes in slabs, bait stations around the perimeter)

Typical repair costs: Active treatment costs $500 to $2,500. Structural repair of termite-damaged wood ranges from $3,000 to $20,000+ depending on severity and what has been damaged.

Elevated Radon Levels

A radon test result at or above 4.0 pCi/L is a common finding in Tennessee, especially in the Knoxville and Chattanooga markets. While radon is not a structural defect, it is a health hazard — radon is the leading cause of lung cancer among non-smokers.

The good news: radon mitigation is one of the most straightforward and affordable fixes among major inspection findings. A radon mitigation system typically costs $800 to $2,500 to install and reduces radon levels by 80-99%. Buyers commonly negotiate for the seller to install a system or provide a credit at closing. Read our full guide on radon testing in Tennessee.

FAQ

Can a house fail a home inspection?

No. A home inspection is not a pass/fail test. The inspector documents the condition of the home's systems and components and reports findings to the buyer. The buyer then decides how to proceed — whether to negotiate repairs, request credits, adjust the offer price, or walk away.

What are the most common deal-breakers on a home inspection?

The most common deal-breakers are foundation and structural problems, major roof damage, HVAC failure or end-of-life systems, electrical hazards (such as Federal Pacific panels or aluminum wiring), plumbing issues (such as polybutylene piping), significant water damage or mold, termite damage, and elevated radon levels.

Should I walk away from a home with inspection issues?

Not necessarily. Most inspection findings can be repaired or mitigated. The inspection gives you the information to make an informed decision: negotiate repairs, request a price reduction, budget for future fixes, or walk away if the issues are too costly or complex. Your real estate agent can help you evaluate your options.

What issues can make a home uninsurable?

Federal Pacific and Zinsco electrical panels, polybutylene plumbing, aluminum wiring without remediation, and active roof leaks can all make a home difficult or impossible to insure. Insurance companies may require these issues to be resolved before issuing a policy.