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&nb...