In this episode of fire fundamentals with the ITB fire resistance expert Piotr Turkowski we break down what a fire resistance rating criteria, and what the letters behind ratings like “REI 60” exactly stand for. We use lab experience to explain where the standards are clear, where they are oddly traditional, and where comparisons between products can mislead.

• ISO definition of fire resistance as an ability over time
• What R E I W and M mean in fire resistance classification
• Load bearing capacity as deformation and collapse criteria
• How test loads are applied and why load choice matters
• Integrity E as flames and openings rather than smoke tightness
• Cotton pad test and why it blurs integrity versus insulation
• Insulation I temperature rise limits and prescribed thermocouple points
• Radiation W as a heat flux limit and when it matters
• Mechanical impact M and the wrecking ball style verification
• Why fire resistance time does not add up across layers
• Furnace minutes, strict thresholds, and unknown test uncertainty

If you liked this podcast episode, you will definietely enjoy:

• https://www.firescienceshow.com/070-fire-resistance-is-whatever-you-want-it-to-be-with-piotr-turkowski/ our previous conversation with Piotr about general fire resistance paradigm
• https://www.firescienceshow.com/010-seeking-the-origins-of-standardized-fire-testing-and-ancient-fire-protection-materials-with-john-gales/ another take on the origins of fire resistance

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