Originally Posted By: mpetner
This post was automatically imported from our archived forum.
Walls located on a property line between buildings usually don?t have openings. These walls (party walls) are considered firewalls (as opposed to fire partitions, fire barriers, or some other fire rated assembly) and are continuous from the foundation to about 30? above the roof line. Given that, you may not find any penetrations. Floor framing is allowed to penetrate into party walls but there are provisions that need to be taken in that situation. If you do find a penetration through what you think is a party wall, then it may not be a true party wall after all. It may be some other fire rated assembly. In fact, the building may not be considered an R-3 use, which the IRC really only deals with.
If, by chance, you do know how the wall was made, you can check the ?Fire Resistance - Volume 1 - With Hourly Ratings for Beams, Floors, Roofs, Columns, Walls and Partitions? publication. It?s a publication from Underwriters Laboratories, Inc. This pub gives ratings for numerous fire rated assemblies - more assemblies than you can shake a stick at!