Most Common Issues in a Home Inspection:
What Shows Up Again and Again

Roofing Problems

The roof is one of the first things inspectors examine, and it’s one of the most common sources of findings. Russ walks accessible roofs or uses a drone when walking isn’t safe. The roof evaluation is part of every inspection at no extra charge.

Common roof findings:

Damaged or missing flashings. Flashings are the metal pieces that seal roof penetrations: chimneys, skylights, vents, and roof-wall intersections. When they fail, water finds its way in. Damaged flashings are one of the most common sources of roof leaks.

Worn or aged covering material. Asphalt shingles typically last 20-30 years. A roof showing heavy granule loss, cracking, or cupping is nearing the end of its service life. The inspector will note condition and approximate age. That’s useful for planning, even if the roof isn’t actively leaking.

Improper ventilation. Roof systems need both intake (soffit) and exhaust ventilation to work correctly. Missing ventilation leads to heat and moisture buildup in the attic, which accelerates shingle degradation from underneath and can cause structural damage.

Gutters and downspouts. Clogged, damaged, or improperly graded gutters are extremely common. Downspouts that discharge at the foundation are a frequent contributor to moisture problems below grade.

Grading and Drainage

Probably the most common single finding across all inspections: soil and landscaping that directs water toward the home instead of away from it.

The standard is simple. Grade should slope away from the foundation at a minimum of 6 inches over the first 10 feet. Flat grade, negative grade (sloping toward the house), and landscape beds built up against the foundation all work against that.

When grading is wrong, water pools at the foundation. Over time, that leads to moisture in basements and crawlspaces, hydrostatic pressure on foundation walls, and, in some cases, foundation movement. It’s often the root cause of other problems in the report.

Correcting grading is usually a manageable project. But it often doesn’t happen until someone flags it. Many sellers don’t know it’s a problem.

The related issues that often come with poor grading: vegetation growing against the siding, wood components sitting in or near soil contact, and downspouts that discharge at grade instead of extending away from the foundation.

Electrical Deficiencies

Electrical findings are common in homes of all ages, but the type changes with the era.

Older homes (pre-1980): More likely to have obsolete or unsafe wiring systems. Knob-and-tube wiring (pre-1940s), aluminum branch circuit wiring (1965-1973), and Federal Pacific or Zinsco panels are all common in the Portland metro and all warrant electrician evaluation.

Homes of any age: GFCI protection is commonly missing. Required by code in bathrooms, kitchens, garages, exterior outlets, and other wet areas, GFCI was not required in older homes. Upgrading to GFCI is relatively inexpensive but shows up in almost every report on a home older than about 20 years.

Common across all ages:

• Double-tapped breakers (two wires on a single breaker terminal when not rated for it)
• Missing knockouts or open junction boxes
• Reversed polarity at outlets
• Missing cover plates at panels or junction boxes
• Improper use of extension cords as permanent wiring

Electrical deficiencies range from minor to serious. A licensed electrician evaluation is recommended whenever there are safety-related findings, or when the panel itself is flagged.

Plumbing Problems

Plumbing findings vary widely by home age. The most common:

Water heater issues. The water heater is one of the highest-frequency sources of deficiencies. Improper installation, missing or improper temperature-pressure relief valve discharge piping, inadequate seismic strapping in earthquake zones, corrosion at connections, lack of expansion tank on closed systems, and units at or past their service life (typically 10-15 years) all show up regularly.

Leaking fixtures. Dripping faucets, running toilets, slow drains, and small leaks at supply connections under sinks are all common maintenance findings. Not urgent, but worth addressing.

Galvanized steel supply lines. In homes built before about 1960, original galvanized supply piping is often still in place. Galvanized pipe corrodes from the inside, reducing flow over time and eventually failing. The exterior can look intact while the interior is nearly blocked.

Improper drainage slope. Drain lines need to slope adequately for waste to clear. Flat or back-pitched drain lines cause slow drainage and repeated clogs. This is often found in plumbing added later by non-professionals.

Missing cleanouts, improper trap configurations, undersized supply lines. These are installation-related deficiencies that show up in both older homes with original plumbing and newer homes with DIY modifications.

Attic Problems

The attic is one of the most revealing spaces in a home. What goes wrong up there often tells you what’s happening with the roof, the insulation, the HVAC system, and the overall maintenance of the home.

Inadequate insulation. This is extremely common, especially in older homes. Energy codes have changed significantly over the past 40 years. Many Portland-area homes have far less insulation in the attic than current standards require. The result is heat loss in winter, heat gain in summer, and elevated energy costs year-round.

Ventilation problems. Attic ventilation requires balance between intake and exhaust. Blocked soffit vents, missing baffles that prevent insulation from covering the intake vents, and inadequate ridge or gable venting all create conditions for moisture buildup and condensation.

Bathroom exhaust fans vented into the attic. This is extremely common and always wrong. Exhaust fans are supposed to vent to the exterior. When they terminate in the attic, they dump moist air directly into the space, creating condensation on the sheathing, mold growth, and eventually structural damage.

Evidence of past or active leaks. Stained or dark sheathing, rusted fasteners, or soft sheathing at penetration points all indicate water has gotten in. Knowing whether it’s active or historic is important, and it goes in the report.

Crawlspace and Basement Conditions

Homes in the Pacific Northwest sit on crawlspaces more often than basements, and crawlspace conditions are among the most consistently flagged areas in regional inspection reports.

Standing or pooled water. Any standing water in a crawlspace means the drainage system isn’t working. This needs to be addressed.

High moisture levels. Even without standing water, elevated humidity in a crawlspace leads to wood moisture content high enough to support mold growth and wood decay over time. Vapor barriers, proper ventilation, and exterior drainage all play a role.

Inadequate vapor barrier. A 6-mil or thicker plastic vapor barrier should cover the entire crawlspace floor. Missing, damaged, or undersized barriers are common in older homes.

Pest damage or conducive conditions. Wood in or near soil contact, debris left in the crawlspace, and moisture-damaged framing all create conditions that attract wood-destroying organisms.

Missing or inadequate insulation. Insulation on crawlspace walls or the underside of the subfloor varies significantly across homes. Missing insulation means heat loss from the floor above and, in unconditioned crawlspaces, pipe freeze risk.

HVAC System Findings

Heating and cooling systems fail. Most buyers know this. What they want to know from the inspection is where in the lifespan a system sits and whether there are current problems.

Age and typical service life. Furnaces typically last 15-20 years, air conditioners 12-15 years, heat pumps similar. An inspector won’t predict failure, but they note age. A 22-year-old furnace that currently operates is close enough to end of life that budgeting for replacement is worth doing.

Inoperable equipment. If the system won’t run at the time of inspection, that goes in the report clearly. The inspector notes what was tested and what wasn’t.

Dirty filters, uninsulated ducts, disconnected returns. Common maintenance findings. Not emergencies, but they affect system performance and efficiency.

Heat exchanger concerns. Serious. A cracked heat exchanger on a gas furnace can allow combustion gases, including carbon monoxide, to enter the living space. Heat exchanger condition can’t be judged in a visual inspection, so any concern warrants immediate licensed HVAC contractor evaluation.

For Portland buyers, heat pump and ductless mini-split systems are increasingly common. These have their own failure modes and a good inspector will evaluate them accordingly.

What Makes the Portland Metro and SW Washington Different

Some findings show up more often here than in other markets, because of the climate, the soils, and the eras when much of the housing was built.

• Attic moisture. Wet winters, temperature swings, and older homes’ ventilation and air-sealing gaps make attic moisture one of the most consistent findings in the region. In many older homes, warm interior air escapes through unsealed attic penetrations, reaches the cold roof sheathing, and condenses.
• Crawlspace moisture. Many homes in the Portland metro and SW Washington sit on crawlspaces rather than full basements. Crawlspaces collect moisture from the ground and from humid air. Without an adequate vapor barrier and good drainage, that moisture affects the framing above over time.
• Soil movement. Clay soils in parts of the metro shrink and swell as seasonal moisture changes. That can show up as foundation movement, cracked flatwork, and grading that shifts around the foundation over time.
• Federal Pacific and Zinsco panels. Both turn up regularly in pre-1980 homes in the area, and both get flagged for electrician evaluation when found.
• Older plumbing materials. Polybutylene pipe (late 1970s to mid-1990s) and galvanized steel supply pipe (common before the 1960s) are both found in the area’s housing stock. Each has documented concerns that get noted when present.

What to Do With a Long List

Most inspection reports list a lot of items. That’s normal. It doesn’t mean the home is a disaster.

Sort findings by severity. Address safety items and specialist referrals first. Then major system deficiencies. Then maintenance items. A 60-item report where 55 items are maintenance and 5 are significant findings is a different situation than 10 items all flagged for specialist evaluation.

Use the contingency period. If the report includes specialist referrals (and most do), get those scheduled immediately. That’s what the window is for.

And if you have questions about what something means, ask your inspector. Reports are written to be clear, but reading 70 pages of technical documentation after a stressful purchase process isn’t always straightforward. A quick call can clear up a lot.

For a breakdown of what’s included in every inspection and what’s available as an add-on, see the buyer’s home inspection page. To book, use the online scheduler. First-time buyer? The first-time homebuyer guide is written for you.