National Home Inspector Examination® (NHIE) cheat sheet

Foundation crack classification: hairline shrinkage cracks (under 1/16 in, vertical, no displacement) are cosmetic; cracks wider than 1/4 in, diagonal cracks at corners, or any crack with offset/franciscan displacement indicate differential settlement and warrant a structural referral.

Floor joist notching and boring limits (dimensional lumber): notches only in the top third of the member, max depth 1/6 of joist depth, never in the middle third of the span; bored holes max diameter 1/3 of joist depth, located at least 2 in from top and bottom edges, with no holes within 2 in of a notch.

Deck ledger attachment is the leading deck failure point: ledger must be attached with through-bolts or lag screws of at least 1/2 in diameter, with correct flashing over the ledger; band-joist-to-ledger attachments and toe-nailed ledgers are reportable defects.

Roof framing: a rafter is a sloping member in bearing at ridge and wall plate; a ceiling joist resists rafter thrust at the plate. Missing collar ties or rafter ties in the upper third of the attic is a reportable framing condition.

Structural wood decay indicators: probe with an awl at sill plates, rim joists, and under-window framing; soft or punky wood, frass, and staining indicate rot or insect damage requiring a specialist.

Masonry chimney rule: chimneys must be at least 3 ft above the highest point where they pass through the roof and at least 2 ft higher than any roof surface within 10 ft horizontally.

Slab-on-grade: absence of a visible vapor retarder or capillary break, plus efflorescence or moisture staining at the slab perimeter, is reported as a moisture condition, not a structural failure.

Load path principle: report any discontinuity in the vertical load path (beam ends not bearing on posts, posts not bearing over foundation walls, cantilevers without proper back-span) as a structural concern.

GFCI protection is required in bathrooms, kitchens (countertop receptacles), garages, unfinished basements, outdoors, crawl spaces, and within 6 ft of sinks and laundry areas; test with the built-in test/reset button and report non-responsive devices.

Receptacle testing: an open ground reads as an open circuit on a three-light tester; a reversed polarity reads as hot/neutral swap; a tester cannot detect a false ground (neutral-to-ground bond), so report suspected bootleg grounds for electrician evaluation.

Service panel rules: double-tapped breakers (two conductors under one terminal not listed for it), undersized service conductors, and missing bonding of the panel enclosure are reportable; a panel with a fuse box and no main disconnect should be flagged.

Water heater TPR valve: the discharge pipe must terminate within 6 in of the floor (or to the exterior), be the same diameter as the valve outlet, and must not be capped, reduced, or trapped; a missing or plugged TPR extension is a safety hazard.

Furnace inspection: check for a cracked heat exchanger, correct flue slope (rise of at least 1/4 in per foot toward the chimney), and adequate combustion air; a rusted flue or back-drafting at the draft hood indicates unsafe operation.

Gas appliance connectors: flexible connectors must not pass through walls, floors, or ceilings, must not be concealed, and must be listed; a shutoff valve must be in the same room and within reach of the appliance.

Water supply piping: identify material (copper, PEX, CPVC, galvanized steel, polybutylene). Polybutylene and galvanized steel are reportable as aging/failure-prone materials; note visible corrosion or active leaks.

Dryer vent rules: smooth rigid or semi-rigid metal duct, maximum developed length of 25 ft for a 4-in duct (minus 5 ft per 90-degree elbow), terminating outdoors with a backdraft damper; vinyl flex duct is a fire hazard.

A home inspection is a visual, non-invasive, good-faith examination of readily accessible systems and components; it is not a code-compliance inspection, a warranty, or a technically exhaustive evaluation.

The written report must identify inspected systems, describe material defects observed, and state what was not inspected and why (inaccessible, unsafe, concealed, or disclaimed).

Material defect definition: a condition with a significant adverse effect on the value, safety, or desirability of the property, or one that would not be readily observable to an ordinary buyer.

Client confidentiality: report findings to the client; sharing results with third parties (agents, sellers) requires client consent, and the inspector should not accept compensation from parties with a financial interest in the transaction.

Continuing education: many states require a set number of CE hours per license cycle (commonly 16-24 hours) plus adherence to a published Standards of Practice and Code of Ethics.

Limits of liability clauses must be conspicuous and are unenforceable in some jurisdictions; the inspector's best protection is a signed pre-inspection agreement, documentation of limitations, and consistent report language.

Pricing and scope: fees are set by the inspector, not by real estate agents; inspectors should not negotiate fees with agents or offer repair services on properties they inspect (conflict of interest).

Report language should be factual and condition-specific ("observed," "not observed," "recommend evaluation by a licensed contractor"), avoid predicting remaining life, and avoid guarantees.