Reply #29: If I could add something... [View All]

[quickesst]

My job is commercial metal stud framing and drywall installation. I'm the one who builds the walls and installs the drywall around those electrical rooms. There are at the least four (4) layers of 5/8 drywall surrounding the entire room, plus insulation, and fireproofing around the complete perimeter and interior where the walls meet the ceiling for a two hour rating. That means a fire will have to directly burn the area for two full hours before penetration. The concrete floor above serves as the fire rating for the ceiling. It really doesn't matter if the electrical room IS next to an outer wall. Unless the rooms took a direct hit, it would be hard to imagine a fire penetrating a two-hour rated wall that burned for less time than that. Also note: Electrical rooms have no windows. It would completely destroy the mandatory fire-rating. The flashes I saw were occurring well below the collapsing building. Just a point of interest from what I believe some of you refer to as a lurker. Thanks!
quickesst

Please note: I have not worked on anything near as large aa the WTC, but I would suspect that the fire-ratings for those buildings would either meet or exceed the requirements I'm used to. Thanks.