V-Pattern
Definition
A V-shaped area of heat and smoke damage on a vertical surface, produced by the upward cone of the fire plume; the apex indicates the area of greatest sustained heat intensity at that surface, not necessarily the ignition point.
- Pattern shape on vertical surfaces
- Narrow at the base, widening upward in a V or cone shape.
- Physical cause
- Heat and smoke rising in a buoyant plume from a low point of origin.
- Investigative use
- Classic indicator for locating the area of origin at or near floor level on a wall.
Common questions
What does a V-pattern tell a fire investigator?+
A V-pattern is an upward-widening burn mark on a wall, narrow at the bottom and wider as it rises. The point (apex) of the V shows where the heat was most intense at that surface, which helps identify the area of origin. The pattern is caused by hot gases rising from the fire's starting point in an upward cone shape.
Can a V-pattern confirm where a fire started?+
A single V-pattern on a wall is a strong indicator of point of origin at the floor-level base of that pattern. However, the apex tells you where heat was most intense, not necessarily the exact ignition point. If multiple low V-patterns appear on different walls, this suggests separate ignition points and is a key sign of arson.
Why do V-patterns form in fires?+
When a fire starts at a low point, hot gases and smoke rise upward in a buoyant plume. This rising column of heat spreads outward as it goes higher, creating a cone-shaped burn pattern on vertical surfaces. The narrow point stays at ground level where the fire originated, and the burn widens naturally with the expanding plume.
Related terms
- Fire Tetrahedron
- The model of sustained combustion requiring four concurrent elements: fuel, oxidiser, heat, and an uninhibited radical chain reaction. Replacing the older fire...
- Flashover
- The near-simultaneous ignition of all exposed combustible surfaces in a compartment, occurring when the upper gas layer reaches approximately 600°C and radiative...
- Annealing
- The heat-induced reorganisation of the crystal structure of steel at temperatures above approximately 720°C, resulting in reduced hardness and tensile strength; measurable...
- Arc Bead
- A small, rounded, resolidified deposit of copper or aluminium formed when an electrical arc melts the conductor and the material rapidly re-solidifies;...
- ASTM E1618
- Standard Test Method for Ignitable Liquid Residues in Extracts from Fire Debris Samples by Gas Chromatography-Mass Spectrometry. The active analytical standard defining...
- Backdraft
- A deflagration event triggered when air is suddenly admitted to a compartment where a fire has been oxygen-depleted but has continued to...
- Blast Over-Pressure
- The shock-wave pressure above ambient atmospheric pressure. Mapped in concentric zones around the seat: Zone I (over 70 kPa, total destruction), Zone...
- BNSS Section 176(3)
- Bharatiya Nagarik Suraksha Sanhita 2023 provision requiring a forensic-team visit to the scene of any offence punishable with seven years or more...
- Calcination
- Bone transformation at temperatures above 700°C: complete combustion of the organic collagen fraction, leaving only white hydroxyapatite mineral. Destroys DNA, collagen (precluding...
- Char Depth Gradient
- The depth of charred wood measured at multiple points; deeper char means longer exposure, so the gradient reveals the direction of fire...
- Char-Depth Probe
- A calibrated steel probe inserted perpendicular to a charred wood surface to measure the depth of charring; used systematically across a scene...
- Crater Analysis
- Measurement of crater diameter, depth and ejecta direction at the seat of explosion. Feeds Hopkinson-Cranz scaling to estimate explosive type and charge...
Explained in these topics
- Fire and Arson Investigation: Cause, Origin and Burn PatternsClassic upward-diverging burn pattern on a vertical surface, narrow at the point of origin and wider above. Caused by the buoyant plume of hot gases.
- Fire and Burn Pattern InterpretationAn upward-widening burn pattern on a vertical surface, with the point of the V at or near the floor-level origin. The classical primary indicator for point of...
- Investigation of Explosion and Arson CasesWall scorch pattern that widens upward from a low point of origin. Diagnostic of natural fire growth; multiple low V-patterns suggest separate ignition points...
- Origin and Cause: V-Patterns, Char Depth, Electrical IndicatorsA V-shaped area of heat and smoke damage on a vertical surface, produced by the upward cone of the fire plume; the apex indicates the area of greatest sustaine...