What Does a Home Inspector Look At?
Every major system, every accessible area, from roof to foundation. Here’s a map of what gets examined during a standard home inspection.
People ask this question because they want to know what they’re paying for. Fair enough. The short answer is that a standard home inspection covers every major system in the home, from the roof surface down to the crawlspace floor. That’s a lot of ground.
The longer answer is below. This post walks through every area and system inspected, what specifically gets checked in each one, and what makes Portland-area homes distinct in each category. If you want to know what’s NOT included, that’s covered at the end.
The scope of a home inspection is defined by the Oregon and Washington standards of practice for licensed home inspectors, which govern what inspectors are required to examine. As a Certified Master Inspector® with 3,000+ inspections completed, I also include thermal imaging and moisture meter readings on every inspection at no extra charge. Those tools can point to things a visual inspection alone can miss.
The Roof
The roof is the first thing I evaluate on most inspections. I walk it when conditions allow. When the pitch is too steep or conditions are unsafe, I use a drone or inspect from the eaves with binoculars and document what’s accessible. Either way, the roof gets a real look, not a ground-level glance.
Here’s what’s being checked: the roofing material itself (shingles, tiles, metal panels), the condition and age, flashing at all penetrations (chimneys, vents, skylights, valleys, and roof-to-wall transitions), the ridge cap, gutters and downspouts, and whether downspouts terminate in a way that directs water away from the foundation. Chimneys get their own look, including the cap, crown, and visible mortar condition.
Flat or low-slope sections get special attention because water management is more critical when there’s less pitch helping it run off. Roof vents are checked for condition and blockage. Skylights are checked from above and below for signs of water intrusion around the frames.
Granule loss on asphalt shingles is normal as a roof ages. What matters is how much, and whether the remaining shingles have enough material left to protect the deck below. A roof near the end of its typical service life and a newer one are both documented, but they tell a very different story about near-term costs.
The Attic
The attic is one of the most informative areas in any home. Problems at the roof level often show up first in the attic, not on the roof surface. I fully enter every attic that allows safe access.
Insulation is evaluated for type (blown-in fiberglass, cellulose, batts, spray foam), depth, and coverage. Thin or missing insulation over exterior walls is a common finding. Oregon and Washington have minimum insulation requirements, and many older homes fall short of them.
Ventilation is checked carefully. Attics need balanced airflow, intake at the soffits, exhaust at the ridge or gable, to stay dry. Blocked soffit vents or inadequate ridge ventilation create conditions where moisture accumulates. In Portland’s climate, that moisture often leads to mold on the roof sheathing. It’s one of the most common attic findings I document.
The roof framing is inspected from below: rafters, collar ties, ridge board condition, and whether any repairs or modifications look structurally sound. The roof deck (sheathing) is checked for staining, soft spots, and signs of active or past leaks.
Exhaust fans matter in the attic. Bathroom and kitchen exhaust fans that vent into the attic rather than outdoors are a moisture problem and a common installation error. I find them on a regular basis, especially in older homes and in homes where bathrooms have been updated without proper fan installation.
Thermal imaging adds another layer here. Temperature differentials in attic framing or along ceiling planes can point to possible moisture and insulation gaps that aren’t obvious to the eye.
The Exterior
The exterior inspection starts at the lot level and works inward. Grading and drainage are evaluated first. Water should flow away from the foundation, and when the soil has settled or graded the wrong direction, every rain event sends water toward the house. I document grading conditions and identify areas where correction is needed.
Siding is inspected for condition, proper installation, and visible signs of moisture intrusion. This varies by material. Wood siding can rot at the bottom courses, at window trim, and wherever caulk has failed. Fiber cement siding can delaminate if it’s been installed with bottom edges too close to rooflines or grade. Vinyl siding can show damage or gaps that let water behind the cladding.
Windows and doors are evaluated from the outside for caulk condition, flashing, and frame condition. Trim boards are checked for rot, especially at horizontal surfaces where water can sit. Decks and porches get a thorough look, including ledger board attachment, post bases, handrail height and security, and the condition of the decking surface itself.
The foundation is visible at grade level on most homes. I look for cracking patterns, signs of settlement, efflorescence (indicating water movement through masonry), and any areas where soil is in contact with wood framing. Vegetation growing against the foundation is noted, as root systems can move soil and eventually put pressure on foundation walls.
Foundation and Structural Components
A home inspector looks at the visible, accessible structural components. That means the foundation at grade and in the crawlspace, floor framing, posts and beams, rim joists, and any structural modifications that are visible. Inspectors don’t remove wall coverings or open up finished spaces to look at structural elements behind them.
Foundation cracks are documented with attention to pattern, direction, and any signs of active movement. Horizontal cracks in masonry or poured concrete walls are more concerning than vertical cracks. Stair-step cracking in brick or block follows mortar joints and often indicates differential settlement. Any crack with displacement (one side higher than the other) gets flagged for specialist evaluation.
Structural modifications, like removed walls, cut joists, or notched beams, are noted. When something looks concerning, a structural engineer referral is the right next step. That’s not a failure of the inspection, it’s the inspection working correctly.
The Electrical System
The electrical inspection starts at the main panel. I identify the panel type and manufacturer, note the service size, check for double-tapped breakers or neutrals, look at the wiring type entering the panel, and verify that breakers are properly sized and labeled. The panel’s brand matters in Portland because certain manufacturers (Federal Pacific, Zinsco) are found in older homes and have documented performance concerns.
From the panel, I look at wiring throughout the accessible areas of the home. In older Portland homes, that often means identifying knob-and-tube wiring or aluminum wiring, both of which warrant licensed electrician evaluation. Wiring in the attic and crawlspace is visible and checked during those portions of the inspection.
A representative number of outlets and switches are tested throughout the home. Accessible GFCI outlets (the ones with the test/reset buttons, required near water sources) are tested for proper function. AFCI protection, required on most living-area circuits in newer construction, is noted where present or absent. Ungrounded outlets in older homes are documented.
Smoke detectors and carbon monoxide detectors are checked for presence and function. Oregon and Washington both have specific requirements for these, and many older homes aren’t current on CO detector placement.
Exterior outlets are checked for GFCI protection and covers. The service entrance where power enters the home is inspected for weatherhead condition, drip loops, and any visible damage to the service conductors.
The Plumbing System
Plumbing gets evaluated from the supply side through the drains. Supply lines are identified by material: copper, CPVC, PEX, galvanized steel, or polybutylene (a problematic material found in some 1980s-90s homes). Pipe material matters because each has a different expected lifespan and failure mode.
Water pressure is tested. Low pressure can indicate corroded galvanized lines, partially closed shutoffs, or pressure regulator problems. Very high pressure can stress fixtures and supply lines. I test pressure at a representative hose bib and note conditions throughout.
Fixtures are run during the inspection. Sinks, tubs, showers, and toilets are tested for supply function, drain performance, and any signs of leaking at the supply connections or drain traps. I look under the sinks. Slow drains, water staining in cabinets, and corroded shut-off valves all get documented.
The water heater gets a close look: age (visible on the data plate), fuel type, capacity, flue condition (on gas units), pressure relief valve and discharge pipe, and whether the unit is properly secured against earthquake movement. Portland homes have a lot of older water heaters. The typical lifespan is 10-15 years, and many of the ones I see are at or past that mark.
Drain and vent pipes are checked where accessible, primarily in the crawlspace and at fixtures. Visible sections of cast iron, ABS, or PVC drain lines are evaluated for condition and proper slope. Sewer lines themselves are underground and not part of the standard inspection. A sewer scope, arranged separately through a plumber, is the right tool for those.
Heating and Cooling
Heating systems in the home are turned on and evaluated. Gas furnaces and heat pumps are the most common in the Portland area. Oil furnaces show up occasionally in older homes. I check operation, filter condition, distribution (are registers delivering conditioned air?), thermostat function, and whether the system can maintain its set temperature.
Gas furnaces get additional attention: flue pipe condition and proper slope, the visible portions of the heat exchanger where accessible (a crack can allow combustion gases into the home’s air supply), and carbon monoxide levels in the return air. A cracked heat exchanger is a safety issue. It doesn’t always show up visually, and elevated CO in the return air is one warning sign worth a specialist’s follow-up.
Heat pumps and air conditioning units are evaluated for age, operation, and refrigerant line condition at the air handler and outdoor condenser. Ductwork is inspected where accessible, including connections, insulation, and whether ducts in unconditioned spaces (attic, crawlspace) are properly sealed and insulated.
If the home has a mini-split system, I test it in both heating and cooling modes where possible. Radiant floor heating, baseboard electric, or wall heaters are all operated and evaluated if present. The inspection includes the heating sources in the home.
The Interior
Every accessible room in the home gets checked. That means walls, ceilings, and floors in every accessible space, including closets. I’m looking for staining (which can indicate water intrusion or past leaks), cracks (which can indicate settling or structural movement), and any signs of previous repairs that may have concealed underlying conditions.
A representative number of windows are opened and closed to verify operation. Thermal pane windows with failed seals show visible fogging between the panes. That’s a common finding in Pacific Northwest homes where the temperature differential and humidity stress sealed units over time.
A representative number of doors are tested for operation. Doors that stick, won’t latch, or won’t open freely can indicate settling or humidity-related swelling. The difference between seasonal swelling (normal) and structural movement (not normal) is something experience helps identify.
Stairs are checked for handrail presence and security, consistent riser height, and tread condition. Fireplaces are evaluated for damper function, firebox condition, and accessible flue condition, though a full chimney inspection requires a chimney sweep with camera equipment. Garage door operation and auto-reverse safety function are tested. The wall and door between the garage and living space are checked for proper fire separation requirements.
The Crawlspace
I enter crawlspaces whenever access is safe. A look from the access hatch isn’t enough. The far end of the crawlspace, farthest from the hatch, is where problems often accumulate because it gets the least attention.
The crawlspace inspection covers the vapor barrier condition and coverage across the full floor area, wood framing throughout including floor joists, rim joists, posts, and beams, signs of moisture or active water, mold or fungal growth, pest evidence, and the condition of insulation, visible plumbing, and ductwork in the space.
I use a moisture meter on framing throughout the crawlspace. Elevated moisture readings show up in wood before visible rot does. Finding elevated moisture early means the problem is still manageable. If it’s missed, a buyer may discover it after the closing.
Crawlspace moisture is one of the most common significant findings in Portland-area home inspections. Clay soils, about 36 inches of annual rainfall, and older vented crawlspace designs combine to make moisture a persistent issue in this region. The vapor barrier, ventilation, and drainage conditions are documented, and I note whether conditions suggest a straightforward repair or something more involved.
Real Inspection Photos
What These Checks Find
Real photos from Russ's inspection reports, from the roof down to the crawlspace.
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Moss on a chimney crown holds moisture against the concrete, which can speed up cracking and let water into the chimney. -
A floor joist cut to fit ductwork. Structural modifications like this are noted and referred for repair. -
Haze between the panes means the window seal has failed. It is a common Pacific Northwest finding and cannot be cleaned off.
What a Home Inspection Does NOT Include
A standard home inspection covers what’s visible and accessible. Some things require specialized equipment, permits, or expertise that falls outside that scope. These are the most common exclusions.
Sewer lines are underground. A sewer scope inspection with a camera is the right tool. It’s a separate service, arranged through a plumber, and worth doing on older homes with clay or cast iron drain lines.
Septic systems require a specialized evaluation by a licensed professional with the right equipment. A standard inspection notes whether the property appears to be on septic but does not evaluate the system.
Underground oil tanks are a significant concern in Portland-area homes built before 1970. They’re invisible from above grade and require a specialist with a metal detector and ground-penetrating radar. This is a separate service, not a standard inspection item. If you’re buying a pre-1975 Portland home, it’s worth asking about.
Pools and spas are a separate add-on service. In-ground pools and spas require their own inspection, covering the pool structure, equipment, plumbing, electrical, and safety features. Free-standing hot tubs are not included.
Concealed areas (behind walls, under slabs, inside chimneys beyond visual access) are not accessible without destructive investigation. The inspector notes conditions at accessible areas and flags concerns that may warrant specialist evaluation of areas that can’t be seen.
What Makes Portland Homes Distinctive by System
- Electrical: Knob-and-tube wiring in pre-1950 homes, Federal Pacific and Zinsco panels in mid-century homes, and lack of AFCI protection are all common finds in Portland’s older housing stock.
- Plumbing: Galvanized steel supply lines in pre-1960 homes corrode internally, reducing flow over time. Polybutylene supply lines in some 1980s-90s homes have a documented failure history.
- Crawlspace: Moisture is endemic in Portland-area crawlspaces. Clay soil, high annual rainfall, and older vented designs create persistent conditions that require vapor barriers at minimum and encapsulation in chronic cases.
- Heating: Older oil furnaces still exist in some Portland homes. Furnace flues and oil supply lines require careful evaluation. Some homes have converted from oil but retained underground tanks.
- Underground oil tanks: Pre-1975 Portland homes may have a buried heating oil tank. These are not visible during a standard inspection and require a specialist evaluation. A buyer’s inspection will flag signs that suggest a tank may be present, but confirmation requires a separate service.
- Sewer lines: Many Portland neighborhoods have clay sewer laterals from the mid-20th century. Root intrusion and bellying are common. A sewer scope is worth arranging separately through a plumber for most older Portland homes.
If you want to know what to expect on inspection day or have questions about add-on services like radon testing, mold testing, or pool inspection, the buyer’s inspection page has the full detail. And if you’ve wondered about the difference between what inspectors look at versus what they’re specifically looking for, that’s covered in the companion post on what triggers concern during an inspection. Thermal imaging comes standard, no added cost. Read more about why it matters in the thermal imaging overview.
Frequently Asked Questions
Not as part of a standard home inspection. Sewer lines are underground and can’t be visually inspected without a sewer scope camera. A sewer scope inspection is a separate service, arranged through a plumber. In the Portland area, it’s common and worthwhile for older homes, since clay sewer lines from the mid-20th century can have root intrusion, bellying, or deterioration that a standard inspection won’t catch.
Yes. Every accessible room is checked. The inspector looks at walls, ceilings, floors, windows, and doors in each room. Closets are included. Areas that are blocked by stored belongings or locked may be noted as inaccessible in the report.
The attic inspection covers insulation type and depth, ventilation conditions, roof framing and deck from below, signs of moisture or mold on the sheathing, and whether exhaust fans from bathrooms and the kitchen are properly vented out of the home rather than into the attic space. Thermal imaging, included at no additional charge on every inspection, can reveal temperature differences suggesting hidden moisture.
The crawlspace inspection covers vapor barrier condition and coverage, wood framing including joists and rim joists, signs of moisture or active water, mold or fungal growth, insulation condition, visible plumbing and ducting, evidence of pests, and the condition of structural posts and beams. A moisture meter is used on framing throughout the space. Full entry is required to inspect the far reaches of the crawlspace.
Yes. The garage is part of the inspection. This includes the garage door and auto-reverse safety function, the wall and door separating the garage from the living space, electrical outlets, and any visible structural or water intrusion concerns. Attached garages have specific fire separation requirements that get checked.
Not as part of a standard inspection. Pool and spa inspection is a separate add-on service. It covers the pool structure, equipment, plumbing, electrical, and safety features including fencing and drains. In-ground spas are included. Free-standing hot tubs are not.
Inspectors cannot inspect things that are concealed, underground, or require specialized equipment. This includes sewer lines (need a scope), underground oil tanks (need a specialist), behind walls, under concrete slabs, inside chimney flues (need a chimney sweep), and septic systems (need a septic evaluation). These are common specialist referrals after a home inspection.
Yes, in accessible areas. Attic insulation is evaluated for type, depth, and coverage. Crawlspace insulation is checked during the crawlspace inspection. Wall insulation isn’t visible without opening walls, so inspectors note what’s accessible and observable. Thermal imaging can sometimes suggest insulation gaps that wouldn’t otherwise be visible.
