CFI (Flooring Installation Certifications) cheat sheet

Chain of custody: a chronological, signed record of every person who handled an item from seizure to courtroom; any unexplained gap supports a challenge to authenticity and can make the item inadmissible.

Contemporaneous notes rule: field notes made at the time of an inspection or incident carry more weight than later reconstructions; if notes must be rewritten, retain the original and record the reason for rewriting.

Report content baseline: date/time, location, identity of all present, observations versus opinions clearly separated, measurements with units and instrument used, photographs with scale reference, and a closing statement of disposition.

Correction protocol: never obliterate an entry; strike a single line through the error, initial and date it, and write the correct entry adjacent so the alteration is transparent on its face.

Safety hierarchy of controls, most to least effective: elimination, substitution, engineering controls, administrative controls, personal protective equipment. PPE is the last line of defense, not the first.

Common documented hazards: energized circuits, confined spaces with oxygen deficiency, slip/trip/fall surfaces, unguarded machinery, and hazardous atmospheres; each requires an entry-level assessment before work begins.

Photograph sequence: overall scene, mid-range context, then close-up with scale; log each frame number against a description so the photo set can be tied to the report without ambiguity.

Retention: case files, photographs, and physical evidence are retained per jurisdiction schedule; destruction must be authorized in writing and logged so a later challenge cannot allege spoliation.

Ohm's law: V = I × R; power: P = V × I = I²R = V²/R. Use these to test whether a stated current, voltage, and resistance set is internally consistent.

Series circuit: same current through all elements, voltages add, total resistance is the sum. Parallel circuit: same voltage across branches, currents add, total resistance is less than the smallest branch resistance.

AC power: real power P (watts) = V × I × power factor; apparent power S (VA) = V × I; reactive power Q (VAR) = √(S² − P²). A purely resistive load has power factor 1.0.

Grounding versus bonding: grounding connects the system to earth reference; bonding equalizes potential between conductive parts. Absence of either is a frequent shock and fire cause.

Overcurrent protection: a breaker or fuse is sized to protect the conductor, not the load; a conductor rated below the protection threshold can overheat before the device trips.

Arc flash and shock boundaries are set by incident energy and voltage; approach distances increase with voltage, and energized work requires justification plus rated PPE.

Energy units: 1 kWh = 3.6 × 10⁶ J; 1 horsepower ≈ 746 W. Efficiency = useful output energy ÷ input energy, expressed as a percentage.

Battery and storage hazards: thermal runaway can be triggered by overcharge, internal short, or physical damage; lithium cells vent flammable gas and require isolation of the failed cell.

Two gates for physical evidence: relevance (tends to make a fact of consequence more or less probable) and authenticity (item is what the proponent claims it is).

Chain-of-custody elements: unique item identifier, collector identity, date/time of each transfer, storage location, seal condition, and signature of each custodian.

Best evidence rule: to prove the content of a writing, recording, or photograph, the original is generally required unless an exception (loss, destruction without bad faith, unavailability) applies.

Spoliation: failure to preserve evidence once litigation is reasonably anticipated; consequences range from adverse inference instructions to sanctions, and in some jurisdictions separate tort liability.

Hearsay baseline: an out-of-court statement offered for its truth is generally excluded; documented business records and public records are common exceptions requiring foundation testimony.

Digital evidence: hash values establish integrity, metadata establishes timing, and the acquisition must be documented as a forensic image rather than a working copy.

Physical collection rules: photograph before moving, package each item separately, use breathable containers for biological or damp items to prevent mold, and seal with tamper-evident tape.

Opinion testimony by a lay witness is limited to rationally based perceptions helpful to clear understanding; expert opinion requires qualification, reliable method, and fit to the facts.

Fire tetrahedron: fuel, oxygen, heat, and the uninhibited chemical chain reaction. Removing any one element extinguishes combustion.

Class A: ordinary combustibles (wood, paper, cloth) - water and foam are effective; the cooling effect is primary.

Class B: flammable and combustible liquids and gases - smothering, foam, dry chemical, or CO₂; water fog may be used only by trained personnel because a solid stream spreads fuel.

Class C: energized electrical equipment - use non-conductive agents (CO₂, dry chemical); secure power first, after which the fire is reclassified by the burning material.

Class D: combustible metals (magnesium, sodium, titanium) - requires a dry powder formulated for that metal; water and standard extinguishers can react violently.

Class K: cooking media involving animal or vegetable fats - wet chemical agent saponifies the fat; a Class B extinguisher is not a substitute.

Extinguisher rating notation: a number-letter pair, e.g., 2-A:10-B:C, where the number before A is water-equivalent extinguishing capacity and before B is square feet of flammable liquid fire a non-expert can extinguish.

PASS technique: Pull the pin, Aim at the base of the fire, Squeeze the handle, Sweep side to side; evacuation and alarm come before any extinguisher attempt.

Expert admissibility (federal standard): qualifications, sufficient facts or data, reliable principles and methods, and reliable application of those methods to the facts.

Daubert reliability factors: testability, peer review and publication, known or potential error rate, existence of standards and controls, and general acceptance in the field.

Expert witnesses may offer opinions; fact witnesses testify to observations. An expert's report and testimony must stay within the scope of disclosed opinions.

Privilege: attorney-client and work-product protections can shield investigation materials; a report prepared in anticipation of litigation may be discoverable if the protection is waived or the material is used offensively.

Testimony structure: qualify the witness, establish the foundation for each opinion, state the opinion, then explain the basis. Concede unknown points rather than speculate.

Cross-examination targets: scope beyond expertise, reliance on unverified data, chain-of-custody gaps, methodology error rate, and prior inconsistent statements in reports or depositions.

Negligence elements: duty, breach, causation (actual and proximate), and damages. An investigation report should address each element the claim depends on.

Spoliation and perjury exposure: altering notes or testifying beyond the record creates independent liability; preserve drafts and disclose corrections rather than concealing them.

Indemnity principle: the insured is restored to pre-loss financial position, not improved; betterment is deducted from a repair or replacement settlement.

Insurable interest must exist at the time of loss; a party with no financial stake in the property cannot recover for its damage.

Coinsurance clause: if carried limit is below the required percentage of value, recovery is reduced proportionally - payment = (carried ÷ required) × loss, subject to the policy limit and deductible.

Actual cash value = replacement cost − depreciation; replacement cost value pays new-for-old without depreciation. The policy defines which applies and to what property.

Subrogation: after paying a claim, the insurer steps into the insured's shoes against the at-fault party; the insured cannot settle with that party in a way that prejudices the insurer's recovery.

Deductible applies per occurrence unless the policy states otherwise; a separate deductible often applies to wind, hail, or named-storm losses.

Exclusions commonly litigated: intentional acts, wear and tear, faulty workmanship, ordinance or law upgrades, and earth movement; the burden of proving an exclusion generally falls on the insurer.

Claims documentation: proof of loss, inventory with ages and values, photographs, receipts, and expert reports; late or incomplete proof of loss can prejudice coverage.

Vehicle crash reconstruction: momentum and work-energy methods both require documented scene data - skid or yaw marks, crush depth, rest positions, and drag factors by surface type.

Critical speed from yaw: v = √(15 × f × r) with v in mph, f the coefficient of friction, and r the radius in feet; the same relation estimates rollover threshold.

Skid speed: v = √(30 × d × f) with d in feet and f the drag factor; combined surfaces require a weighted or segment-by-segment calculation.

Marine: gross tonnage is a measure of enclosed volume (not weight); displacement tonnage is the actual weight of water displaced by the hull.

Stability: metacentric height (GM) governs initial stability; a small or negative GM indicates tenderness or a tender-to-capsize condition, and free surface effect reduces effective GM.

Collision regulations: power-driven vessels give way to sailing vessels and to vessels not under command or restricted in ability to maneuver; a stand-on vessel must hold course and speed until action is required.

Load line and overloading: exceeding the assigned load line reduces freeboard, raises flooding risk, and is a primary cause of small-vessel swamping and loss.

Fire and fuel hazards aboard: fuel vapor is heavier than air and accumulates in bilges; forced ventilation and ignition-source control precede any engine or electrical work.