Introduction
A home inspection shouldn't be the scariest part of selling your house — but for many sellers, it is. Deals fall apart, buyers renegotiate, and what should have been a smooth closing turns into a stressful ordeal.
The truth? Most inspection surprises are preventable. If you know what inspectors look for and address the common issues beforehand, you'll walk into inspection day with confidence instead of anxiety.
This guide covers the 10 most common things home inspectors flag — and what you can do about each one before the buyer's inspector ever sets foot in your home.
1. Roof & Shingles
The roof is one of the first things an inspector examines, and it's one of the biggest deal-breakers. Buyers don't want a surprise $10,000–$15,000 bill.
What inspectors look for:
- Missing, curling, or cracked shingles
- Damaged flashing around chimneys, vents, and skylights
- Signs of sagging or structural weakness
- Age of the roof — most asphalt shingle roofs last 20–25 years
What to do:
Walk your property and look up. Replace any obviously damaged shingles. If your roof is nearing end-of-life, get a quote so you can price your home accordingly or offer a credit rather than letting the buyer discover it and panic.
2. Electrical Panel & Wiring
Outdated or unsafe electrical systems are a major red flag. Inspectors take this seriously because it's a safety issue.
What inspectors look for:
- Federal Pacific or Zinsco panels (known fire hazards)
- Knob-and-tube or aluminum wiring
- Open junction boxes or exposed wiring
- Overloaded circuits or double-tapped breakers
- Missing GFCI outlets in kitchens, bathrooms, and exterior
What to do:
Have a licensed electrician do a quick safety check. Install GFCI outlets where required — it's inexpensive and eliminates a common finding. If you know you have outdated wiring, disclose it upfront rather than having it discovered.
3. Plumbing & Water Heater
Leaks, slow drains, and aging water heaters are among the most frequently flagged items.
What inspectors look for:
- Dripping faucets and running toilets
- Slow drains or signs of backup
- Water stains on ceilings or walls (evidence of past or active leaks)
- Age and condition of the water heater (most last 10–12 years)
- Corroded or incompatible pipe connections
What to do:
Fix every drip and running toilet — these are cheap repairs that signal neglect when left undone. Check under every sink for moisture or staining. Know the age of your water heater and be ready to discuss it.
4. Foundation & Structural
Foundation issues terrify buyers more than almost anything else. Even hairline cracks can trigger concern.
What inspectors look for:
- Cracks in foundation walls (horizontal cracks are more serious than vertical)
- Uneven or sloping floors
- Doors and windows that stick or won't close properly
- Signs of water intrusion in the basement
What to do:
Most homes have minor settling cracks — these are normal. But if you have significant cracking, bowing walls, or persistent water intrusion, get a structural assessment before listing. Knowing the severity (and having a professional opinion) puts you ahead of the conversation.
5. HVAC System
Heating and cooling systems are expensive to replace, so inspectors examine them closely.
What inspectors look for:
- Age and condition of the furnace (most last 15–20 years)
- Cracked heat exchangers (safety hazard)
- Dirty or clogged filters
- Unusual noises or odours during operation
- Central air conditioning performance and refrigerant levels
What to do:
Replace your furnace filter — it's $20 and shows you maintain the system. Have your HVAC serviced before listing. Keep your service records handy; buyers love seeing a maintenance history.
6. Attic & Insulation
The attic tells an inspector a lot about how well a home has been maintained — and it's where hidden problems often live.
What inspectors look for:
- Adequate insulation (R-values vary by region)
- Proper ventilation (soffit vents, ridge vents)
- Signs of moisture, mould, or condensation
- Evidence of pests or rodents
- Bathroom fans vented into the attic instead of outside
What to do:
Check that bathroom exhaust fans vent to the exterior — venting into the attic is one of the most common (and easily fixable) issues. Look for any signs of moisture or mould and address them before listing.
7. Windows & Doors
Windows and doors affect energy efficiency, security, and livability. Inspectors check every one of them.
What inspectors look for:
- Broken or foggy seals (condensation between panes)
- Cracked or missing glazing
- Difficulty opening, closing, or locking
- Rotting frames or sills
- Missing or damaged weatherstripping
What to do:
Test every window and door. Lubricate sticky tracks, replace broken hardware, and add weatherstripping where it's missing. You don't need to replace foggy windows before selling — but know that inspectors will note them.
8. Grading & Drainage
Water is a home's worst enemy. Inspectors pay close attention to how water moves around (and hopefully away from) your foundation.
What inspectors look for:
- Ground sloping toward the foundation instead of away
- Clogged or missing gutters and downspouts
- Downspouts discharging too close to the foundation
- Standing water or erosion near the house
- Sump pump functionality (if applicable)
What to do:
Clean your gutters and extend downspouts at least 6 feet from the foundation. Re-grade any areas where soil slopes toward the house. These are inexpensive fixes that prevent a major red flag.
9. Smoke & Carbon Monoxide Detectors
This is the easiest item on this list to fix — and one of the most commonly flagged.
What inspectors look for:
- Working smoke detectors on every level and near bedrooms
- Carbon monoxide detectors near sleeping areas and fuel-burning appliances
- Detectors that are expired (most last 7–10 years)
- Missing detectors in required locations
What to do:
Test every detector. Replace batteries. Replace any detector older than 10 years. Add detectors where they're missing. Total cost: usually under $50. There's no excuse for failing this one.
10. Exterior & Decks
Decks, porches, and exterior structures are safety concerns — and inspectors check them thoroughly.
What inspectors look for:
- Loose or rotting deck boards
- Wobbly or improperly attached railings
- Decks not properly ledger-bolted to the house
- Peeling paint or rotting trim on the exterior
- Damaged siding or fascia
What to do:
Walk your deck and test the railings — do they wobble? Tighten or replace fasteners. Replace any rotting boards. Touch up peeling exterior paint. These are visible issues that make buyers question overall maintenance.
Your Pre-Inspection Checklist
Use this checklist to walk through your home before the inspector does:
- ☐ Inspect roof for missing or damaged shingles
- ☐ Install GFCI outlets in kitchens, bathrooms & exterior
- ☐ Fix all dripping faucets and running toilets
- ☐ Check under every sink for leaks or staining
- ☐ Look for foundation cracks and water intrusion signs
- ☐ Replace furnace filter and schedule HVAC service
- ☐ Verify bathroom fans vent to exterior, not attic
- ☐ Test all windows and doors — lubricate or repair
- ☐ Clean gutters and extend downspouts from foundation
- ☐ Test and replace smoke/CO detectors as needed
- ☐ Tighten deck railings and replace rotting boards
- ☐ Gather permits, receipts, and service records
- ☐ Consider a pre-listing inspection