A good home inspection can make the difference between buying a sound home (with normal repair and replacement expenses) and buying a downright money pit. That's why it's absolutely essential to have a house professionally inspected before buying it. And whether you're a home buyer or a seller, it can help to be familiar with the main checklist items an inspection will include.
Roof and Gutters
Inspectors look at the age and overall condition of the roofing to determine how much life it might have left. They also look for a few key elements that prevent leaks; namely, flashing at all transitions. Missing flashing and failed sealant all are red flags that warn the inspector there might be evidence of leaks below.
- Flashing: Is there flashing along all joints where the roof meets walls, dormers and skylights?
- Chimney: Are chimneys properly flashed and sealed? Is the chimney in good condition?
- Penetrations: Do pipes, vents and other penetrations have rubber boots or other flashing, and is it in good condition?
- Shingles: Are any shingles damaged or missing? Are there exposed or popped nails?
House exterior checklist items include siding, trim boards, window and door trim and other finish elements, but basically, inspectors are checking for signs of rot, insect damage and areas where water might be getting into the wall structure.
- Wood materials: Are any touching the ground or within 6 inches of the ground?
- Paint: Is the paint or other protective finish in good condition?
- Trim: Are trim boards well-fastened, without significant gaps that can let in moisture and pests?
- Doors and windows: Do they have flashing or drip edge along the top to keep water away? Are these areas well caulked or otherwise sealed?
- Siding: Is it in good condition (even if it could use a paint job)? If the siding is stucco or masonry, are there open cracks; is mortar missing from brick siding?
Gutters and Drainage
Inspectors want to see that gutters are in good shape and are properly sloped, and that the downspouts direct water away from the house's foundation. Along the same lines, the ground should slope downward away from the house to promote natural drainage. Problems here increase the likelihood of water in the basement or crawlspace.
- Gutters: Are horizontal gutter runs sloped toward the downspouts? Are the gutters straight and properly secured?
- Downspouts: Are there are enough downspouts for the length of gutter runs?
- Downspout outlets: Do the outlets drain water onto ground sloping away from the house? Are downspout extensions and/or drainage blocks used where necessary?
Foundation and Home Structure
The primary structural elements include the foundation and the internal framing of the home. In most cases, these are visible primarily in the basement or crawlspace, where inspectors can view the foundation walls (and concrete footings under the wall) and the floor framing supporting the rest of the house.
- Foundation walls: Are they plumb (perfectly vertical), straight and free of significant cracks?
- Footings: Do they bear on solid soil or rock and have no significant cracking?
- Main support beams: Are they adequately sized and supported? Do support columns bear on concrete pads or footings?
- Floor joists: Are they straight, sound and sized properly for their spans (length)?
- Exterior house walls: Are they straight and plumb (not bowed)?
- Windows and doors: Do the openings look square (plumb and level), not skewed?
- Roof: Is the ridge straight, not saddled? Are the roof planes flat, not dipping or bulging?
Inspectors look for lots of potential problems in attics, including and checks of the structure, insulation and ventilation system. They also make sure homeowners haven't been really stupid and vented their clothes dryers or their bath or kitchen vent fans into the attic.
- Rafters or trusses: Are they properly sized for the roof span? Are they in good condition?
- Floor joists: If the attic space is used for storage or other purposes, are the joists large enough to handle the additional load?
- Roof deck (plywood or boards under the shingles): Any signs of leaks, mold, rot or insect damage?
- Ventilation: Is it adequate for the attic space and home? Are soffit and/or roof vents blocked, restricting airflow?
- Insulation: Are insulation levels appropriate for the local climate, and is insulation installed properly? Any signs of mold or water damage on insulation?
Inspection of the electrical system starts at the service panel, or breaker box (or fuse box). Red flags and unprofessional workmanship at the panel alerts the inspector to check for poor installation elsewhere. Basements and crawlspaces also offer easy access to wiring and other electrical equipment. In the house, inspectors can't see the wiring but can check switches, fixtures and appliances for proper installation and operation.
- Service panel: Is the service capacity up to the modern standard of 150 or 200 amps? Has the panel model been recalled? Are the breakers and wires neat and properly installed?
- Exposed wiring: What is the wiring type and how is it installed? What does the system use for grounding? Are wiring cables properly supported and fastened?
- Junction boxes: Do all junction boxes (which enclose wire splices) have cable clamps for the incoming cables? Are the boxes in accessible locations and do they have covers?
- Switches and fixtures: Do switches, light fixtures, ceiling fans and vent fans work properly?
- Outlets (receptacles): Do multiple receptacles pass the test for proper wiring and grounding? Are there GFCI receptacles in all required locations (kitchens, bathrooms, laundry rooms, garages, outdoors, etc.)?
Plumbing inspections look for signs of leaks, corroded materials and improper pipe configurations. Water pressure and drain performance also can indicate potential problems.
- Water pressure: Is the pressure low/weak at multiple fixtures?
- Water pipes: What are they made of? Are galvanized steel pipe combined with low water pressure (indicating significant corrosion inside the pipes)?
- Drain pipes: Are there signs of leaks? Do the key drains have cleanouts for snaking the drains? What are the pipes made of, and are old metal pipes corroded? Are drain pipes sloped properly?
- Drains: Do the toilets, sinks and tub/shower drain well?
- Septic systems: Has the septic tank been cleaned or serviced recently? What is the condition of the leach field (drainage field)?
- Sewer system: Is there evidence of a recent backup in the main house drain or sewer pipe? Has the sewer drain been scoped with a camera (an optional service performed by a plumber or drain contractor, not a house inspector)?
Water Heater and HVAC
While a typical home inspection will note the age and overall condition of most major appliances, the greatest focus is on the water heater and the heating, ventilation and air conditioning (HVAC) equipment.
- Water heater: Is the tank size/heater capacity suitable for the household? Are all required safety features intact? Is the heater properly vented? How old is the water heater (particularly important with tank-style heaters)?
- Heating system: Is each room adequately served? Does the system operate properly; heat and/or cool the rooms?
- Forced-air ductwork: Are ducts properly sized? Are the joints well-sealed? Are supply ducts insulated?
- Furnace: What is the general age and condition? Is the filter clean?
- Venting: Is the furnace or boiler properly vented? Any signs of corrosion or excessive moisture?
- Air conditioner: Is the outdoor unit properly installed, with a support pad and a suitable location? Is there any corrosion on the unit? Is the unit properly sized for the house? What is the unit's age?
- Boiler (hydronic heating): What is the boiler's age and condition? Is it properly vented? Is the system appropriately zoned?
Most home inspections include a radon test as an optional add-on. The test is done over 48 hours when no one is home. The test is highly recommended and is nothing to fear. High levels of radon can cause cancer, and radon mitigation is no big deal if the house fails the test. It usually takes a professional only a few hours to install a mitigation system and it costs an average of $1,200.
Philip Schmidt is author of Install Your Own Solar Panels, The Complete Guide to Treehouses, and 18 other home-related how-to books. A former carpenter, he has been a full-time writer and editor for over two decades, teaching DIYers about houses and everything we do with them.