I recently posted some information on Engineered Structural Systems, HERE, HERE and HERE. I also discussed the benefits of looking at the recent Underwriter’s Laboratories (UL) test data and report on Structural Stability of Engineered Lumber in Fire Conditions. HERE.

Now in case you didn’t have time to look at the report or to sit down and take the online course online let me again stress the importance that you gain some insights on the Structural Stability of Engineered Lumber in Fire Conditions. The comparative test results related to legacy (conventional) versus modern engineered construction systems is mission critical for any organization that has engineered structural systems and components in occupancies and structures within their jurisdiction or response area.

Operationally, do you have a true sense of the operational time afford your companies while operating within the interior of these structures? It is not business as usual! The time-to-collapse sequences and operational deployment times for interior operations must be redefined and considered in you IAP and tactical deployment. Let me offer two clear examples based upon the UL test results for you to consider.

First, in assembly test systems constructed of 12 inch depth unprotected wooded I-joists, the floor systems collapsed within Six (6) minutes of exposure (from time of ignition). The tests also provides indicators that floor or roof assembly deflection (give or bounce), which has been a universal tactic as an possible indication of imminent collapse, suggests that may not be a reliable indicator, with some floor assembly tests having a deflection of less than 3/4” immediately before structural failure. Add to this carpeting or lightweight concrete coatings, top-side surface temperature (TIC readings) may change little even as the structural integrity of the support system is rapidly diminished below.

Look closely at the third slide in the series posted. Do not, I repeat Do Not fall under the belief that your thermal imaging camera (TIC) will provide adequate indication of fire severity and magnitude beneath the flooring system your companies may be transitioning over. There are operational limitations and readings related to thermal imaging devices while working above fire involved floor or roof areas. In the case of the test results, the surface area reading from the TIC of the carpeted floor was reading 73 degrees F, while the fire involved basement area had an ambient temperature reading of 1330 degrees F and the surface of the underfloor was reading 1274 degrees F. ( a difference of 1201 degrees.) So if your using a TIC to determine the degree of fire impingement on a floor to monitor structural stability and safety while traversing the area, think again. It’s time to rethink certain tactical assignments and the related task-mission-time allotment during tactical deployments. Where will you find your crews while operating above a fire floor within the first six minutes of your operations at a residential structure built in the past five years? How much time do they really have? Think about it. "What you see, isn't what you have.... or may get"