Perimeter Fire Containment

Architects and curtain wall designers have long recognized that the void created between the floor slab and exterior wall if left unprotected, would allow fire and smoke to propagate to the floor above. The logical fix seemed to be to fill the void with fire-resistant material. However, if the void is simply filled with mineral wool and a portion of the spandrel area is left unprotected, the curtain wall will fall, causing the mineral wool to fall out of the void. Once the mineral wool at the void is lost, fire will propagate through the opening, allowing fire to engage combustibles in the floor above.