File:Mortar intumescent.jpg

Summary
Passive Fire Protection Example: 90 minute fire-resistance rated barrier, including fire door on the left, a cable penetration firestop sealed with a firestop mortar and cables coated with an intumescent fire retardant, which reduces the flame-spread along cable jacketing and neutralises hydrochloric acid evolution that may result from fire exposure of the cable jacketing. Another consideration: Steel expands during fires, which results first in pushing of the cable tray against the firestop mortar. Subsequent to the pushing, once steel has reached its critical temperature above 500°C, the cable tray may collapse and the pull on the firestop. Public testing in Germany has verified that properly installed firestop mortar seals are capable of resisting both the pushing and pulling motion that is inevitable as a result of the fire exposure upon Steel cable trays. --Ahering@cogeco.ca 01:40, 7 April 2006 (UTC)