Typically the scenario that was described will not produce a 2-hour fire stop detail. But it is not difficult to restore it to such. There are many existing UL rated firestop details, and I can send you some.
One solution is to restore the wall fire resistance with a fire stop detail including mineral wool and a smoke-&-fire-sealant. Pack mineral wool into the annular gap around the pipe, to a 25-33% compression (don't worry, no one is measuring this) so that the entire thickness, and it is my personal opinion, as suspect as that may be, that this detail is not the essential one that the detail hangs upon. Simply assure yourself the hole in the entire thickness of the wall is filled with mineral wool and the mineral wool is somewhat compacted. This will just about restore the 2-hour FRR. Use at minimum 4 pcf mineral wool. As frosting on the cake of this firestop detail, one often puts a smoke seal. One spreads the elastomerics smoke seal over the mineral wool and extends the sealant 1/2-inch onto the wall and onto the pipe. what type of smoke seal to use depends upon what firestop detail you are looking at. There are many manufacturers. scot deal excelsior fire _______________________________________________ Sprinklerforum mailing list [email protected] http://fireball.firesprinkler.org/mailman/listinfo/sprinklerforum For Technical Assistance, send an email to: [email protected] To Unsubscribe, send an email to:[email protected] (Put the word unsubscribe in the subject field)
