by Jerry Peck - Codeman on Sun Jul 25, 2010 11:37 am
Yes, that opening needs to be sealed off to be tight around the gas line.
Fireblocking is required at each ceiling level and at each floor level. An easy way to fireblock that opening is with a piece of plywood of similar thickness to the plywood used for the floor sheathing above, drill a hole in the piece of plywood - make the hole slightly larger in diameter than the outside diameter of the pipe (example would be 1/2" pipe is approximately 3/4" in outside diameter, thus you would want a 1" size drill), then cut the piece of plywood such that the cut goes through the center of the hole you drilled out (this not only cuts the piece into two pieces which fit around the pipe, but the saw cut makes the hole slightly smaller by the width of the saw blade cut used), now fasten the two piece to the underside of the floor sheathing above such that the two pieces fit around the pipe as tightly as possible, seal the remaining space between the pipe and the plywood.
Jerry Peck - CodeMan
AskCodeMan.com
Construction Litigation Consultant - Retired
Construction and Code Consultant - Semi Retired