Every listing for firestopping plastic pipes through concrete floor allows for bottom collar installation only. What are the reasons for that?
Hi,
A fire collar works by crushing a melting combustible pipe in the event of a fire, preventing the spread of smoke or flames throughout the building. The metal band around the fire collar stops the intumescent material from expanding outside the space. When the intumescent material begins expanding in the heat, it’s unable to expand outwards, and the pressure is contained within the space. The melting pipe will collapse under the pressure, sealing the hole. The intumescent material inside the metal band expands when subjected to a specified degree of heat. Since the natural direction of heat and fire spread is upward, and for the intumescent material in the collar to be activated, the collar will have to be installed on
the side of the fire which is the bottom side of the floor.