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Modern Construction and Fire
Modern Light weight Construction ( High Performance )
Legacy Construction
Fire Effects on the structure
Residential Fire Environment
LIGHTWEIGHT CONSTRUCTIONDEFINITION:
Lightweight construction does not derive its strength from size. Its strength is obtained from multiple members that are in compression and tension.
Additionally, the strength of the individual structural member is dependent on the sum total of the other members; thus, if one member fails, other members may fail.
Legacy ConstructionFull size lumber ( Mass)SpacingNails, bolts, heavy screwsRafters and Timber beams
Lightweight ConstructionSmall sized componentsMinimal amount of safety designed into the systemGussets and GlueTrusses and Engineered BeamsComposite/Vinyl doors and windows
Residential construction:
Greater than 60% of Roof / floor systems since 90’s
Underwriter Laboratories Floor System ObservationsSubfloor temp to 200 f LW: 5:30 Legacy
12:00Surface Temp at 5 Minutes: LW- 85 f Legacy
73 fVisible Smoke: LW- 2:30 Legacy 13:00Visible Flames: LW- 5:50 Legacy 17:50
Average time to Structural FailureLegacy Construction 18 minutesLightweight Construction 6 minutes
Lightweight Construction by the Numbers
Residential Fire EnvironmentModern Furnishings
Synthetic Materials such as PolyurethaneIncreased DamageRapid Fire DevelopmentIncreased Smoke Development
Time it takes for a room to burst into flameLegacy Furnishings 4 minutes 25 secondsModern Furnishings 1 minute 50 seconds
Todays Furnishings… contribute to fires burning bigger and faster than ever before.
Lightweight (HP)Construction and Modern Furnishings
It is not Light Weight (High Performance) construction. The concern is what happens when lightweight construction meets fire.
I like to compare it to a modern High performance automobile, operating in conditions for which it was not intended..
Occupant EscapeReduced from an
avg. of 5 minutes to
2 minutes from the Start of the incident.
Highlights the importance of Smoke detection, Fire sprinkler protection, and an Escape Plan
6 to 8 Minutes until the structure is compromised preventing Fire Department entry
The Problem
Structural Collapse