Home Inspection Glossary

A

AFCI (Arc Fault Circuit Interrupter)

A circuit breaker that detects dangerous arcing — unintended electrical discharge that can ignite a fire — and shuts off the circuit. Required by current building codes in bedrooms and living spaces. An inspector will note which circuits lack AFCI protection.

Attic Bypass

An unsealed gap between the conditioned living space and the attic that allows warm air to escape, reducing energy efficiency and potentially causing moisture buildup in the attic. Common around light fixtures, plumbing chases, and top-plates.

C

Crawlspace

The shallow, unfinished space beneath a home's first floor, typically 18–48 inches high. Inspectors assess crawlspaces for moisture intrusion, wood rot, pest damage, insulation condition, and structural integrity. Access is often limited, and inaccessible areas will be noted in the report.

Combustion Air

The air supply required by gas-fired appliances (furnaces, water heaters) to burn fuel safely and completely. Inadequate combustion air can lead to carbon monoxide production and appliance failure.

Condition Conducive to Mold

A finding that describes moisture, humidity, or organic material present in a location that could support mold growth — even if mold is not yet visible. Common in crawlspaces, basements, and around plumbing leaks. This is a risk indicator, not a mold confirmation.

D

Deferred Maintenance

Upkeep that has been postponed or neglected over time, resulting in deterioration. Common examples include peeling paint, caulk failure at windows, overdue HVAC servicing, and gutter cleaning. Not typically a safety hazard, but left unaddressed, deferred maintenance accelerates deterioration.

Double-Tapping

A condition where two wires are connected to a single circuit breaker terminal that is designed for only one. This is a fire and electrical hazard. Some breaker types are designed to accept two conductors — your inspector will note whether the double-tap is acceptable for that breaker model.

Downspout Extension

A piece attached to the bottom of a downspout to direct water away from the foundation. Extensions (or splash blocks) are critical for preventing water intrusion in basements and crawlspaces. Inspectors frequently note missing or insufficient extensions as a drainage concern.

E

Efflorescence

White, chalky residue on concrete, masonry, or block walls caused by water moving through the material and depositing dissolved salts on the surface. Efflorescence itself is not a structural problem, but it indicates water is migrating through the wall — the underlying moisture source should be addressed.

Expansive Soil

Soil that swells when wet and shrinks when dry, common throughout Colorado's Front Range. The movement can crack foundations, floors, and exterior surfaces. Inspectors look for evidence of differential settlement, cracked slabs, and sticking doors — all potential signs of expansive soil movement.

F

Flashing

Metal or other impermeable material installed at roof intersections, around chimneys, skylights, and penetrations to prevent water from entering. Failed or improperly installed flashing is one of the most common sources of roof leaks. Inspectors check all flashing points for proper installation and sealant condition.

Functional Flow

The ability of a plumbing system to deliver adequate water pressure and volume during simultaneous use. An inspector will run multiple fixtures at once to assess whether pressure drops significantly — a common issue in older homes with corroded pipes or undersized supply lines.

G

GFCI (Ground Fault Circuit Interrupter)

An outlet or breaker that detects ground faults — electricity flowing along an unintended path — and shuts off within milliseconds. Required by code in bathrooms, kitchens, garages, exterior locations, and any area near water. Missing GFCI protection is a common and easily corrected safety finding.

Grading

The slope of the soil around the foundation. Proper grading directs surface water away from the house. Negative grading — soil that slopes toward the foundation — is a leading cause of basement and crawlspace water intrusion.

H

Hail Damage

Impact damage to roofing materials, gutters, siding, and HVAC equipment caused by hailstones. Colorado's Front Range sees some of the highest hail frequency in the country. Hail damage is not always visible from the ground — inspectors access the roof to evaluate shingles, flashing, and gutters for impact marks, bruising, and granule loss.

HVAC

Heating, Ventilation, and Air Conditioning. The combined systems that control indoor temperature and air quality. Inspectors evaluate HVAC for proper operation, age, maintenance history, filter condition, ductwork, and any visible deficiencies. Full mechanical inspection requires systems to be operating.

I

Infrared Thermal Imaging

An inspection technique using a thermal camera to detect temperature differences in surfaces — revealing hidden moisture intrusion, missing insulation, electrical hot spots, and air leakage that are not visible to the naked eye. Available as an add-on service with Front Range Home Inspectors.

Inaccessible

A portion of the property that cannot be safely or reasonably inspected during the course of a standard inspection — such as areas blocked by stored items, areas behind sealed walls, or components that cannot be operated. The inspector will document what was inaccessible and why.

J

Joist

A horizontal structural framing member that supports the floor or ceiling above. Inspectors look for cracked, notched, bored, sagging, or water-damaged joists that may compromise structural integrity.

L

Lateral Sewer Line

The underground pipe that connects the home's drain system to the municipal sewer main. Standard home inspections do not include sewer scope — a camera inspection of this line is a separate service that is often recommended for older homes, homes with large trees near the line, or any home where buyers want certainty about drain condition.

M

Material Defect

A condition that significantly affects the value, habitability, or safety of the property. Material defects are typically the items buyers should consider negotiating or addressing before closing.

Moisture Intrusion

Water entering the building envelope through the foundation, roof, walls, or windows. Moisture intrusion can cause structural damage, mold growth, and deterioration of insulation. Inspectors use moisture meters and thermal cameras to identify both active and historical moisture issues.

P

PCA (Property Condition Assessment)

A commercial property inspection following the ASTM E2018 standard. A PCA evaluates building systems, deferred maintenance, and capital expenditure needs for commercial real estate due diligence.

Polybutylene Pipe

A gray plastic pipe used in residential plumbing from the 1970s through 1990s that has a high failure rate and is no longer manufactured. Its presence in a home is typically flagged as a material concern — replacement is strongly recommended.

Point of Attachment

Where the electrical service entrance cable attaches to the home. Inspectors evaluate the point of attachment for clearance from windows and walkways, weatherhead condition, and the condition of the drip loop.

R

Radon

A naturally occurring radioactive gas that forms from the decay of uranium in soil and rock. Radon is the second leading cause of lung cancer in the United States — and Colorado consistently ranks among the highest-radon states in the nation. Radon is odorless and invisible; testing is the only way to know your levels. The EPA action level is 4.0 pCi/L.

Rafter Tail

The portion of a roof rafter that extends beyond the exterior wall, forming the overhang or eave. Rafter tails are vulnerable to moisture, rot, and pest damage. Inspectors examine them from the ground and from the attic where accessible.

S

Safety Hazard

A condition that poses a direct risk of injury or death to occupants. Inspectors clearly label safety hazards — such as missing GFCI protection, exposed wiring, lack of smoke detectors, or faulty gas connections — and recommend immediate correction regardless of the transaction's outcome.

Serviceable

A condition or component that is functional and performing its intended purpose, though it may be aging or showing wear. Serviceable components typically require monitoring and planned replacement rather than immediate repair.

Standards of Practice

The written guidelines that define the scope, conduct, and reporting requirements for a home inspection. Inspectors follow published Standards of Practice to ensure consistent, defensible evaluations. Front Range Home Inspectors' standards are published at frontrangehomeinspectors.com/standards/.

T

TPR Valve (Temperature & Pressure Relief Valve)

A safety device on water heaters that opens automatically if temperature or pressure exceeds safe limits. Inspectors verify the valve is present, properly installed, and has a discharge pipe routed to a safe location. A missing or corroded TPR valve is a safety deficiency.

Trip Hazard

A surface discontinuity — such as a raised or sunken section of sidewalk, cracked driveway, or uneven deck board — that presents a fall risk. Inspectors note trip hazards in the report as safety items.

V

Vapor Barrier

A plastic sheeting or coating installed in crawlspaces and basements to reduce moisture migration from soil into the structure. An inspector will note missing, damaged, or improperly installed vapor barriers as a contributing condition for moisture and mold.

W

Water Intrusion

See: Moisture Intrusion.

Weatherstripping

Sealing material installed around doors and windows to prevent air and water infiltration. Worn or missing weatherstripping is a maintenance item that affects energy efficiency. Inspectors note it when it contributes to visible drafts or moisture entry.

Wood Destroying Organism (WDO)

Insects or fungi that damage wood — primarily termites, carpenter ants, wood-boring beetles, and wood decay fungi. A standard home inspection evaluates for visible evidence of WDO activity, but a separate WDO inspection by a licensed pest inspector provides a more comprehensive assessment and official clearance letter.