1 hour fire wall

Anyone know what year the 1 hour fire wall for multi family went into effect?

Geesh, I’ve done a few that way even closer to 2000 or so for me.

Now looking at 99 & 2000 IBC any unit less than 5 feet etc… this applies to different formulas for 1 and 2 hour walls. makes reference to http://www.awc.org/Publications/dca/dca3/DCA3.pdf as well for tables and such. Generally if the engineer has something to do with it, you’ll be putting more on that the table says. The reference to 3/8 struct 1 and one layer of 5/8X would be minimal by multifamily construction standards. You would likely by nailing 1/2 struct 1 on E side and 2 layers of 5/8X on I side.

Double (I’ve seen triple too…yuck) layers of Type X…

We had to do party wall type construction with Single layers in middle and 2 layers each side of exposed side to tenant.

I’ve heard different discussions arguments with inspectors etc etc.

Bottom line is to do what the plans say and allow for it (unless it’s an obvious OOOPS). Or in some/many municipalities if you were doing work adjacent to areas affected by new types of requirements for such and enter threshold amounts for work (ie $1000.00 improvements = usually inspector walking around home to check for smoke detectors)

Best thing is to check local municipality and consult building official for that territory.

Don’t know what year they were officially required. However I was required to have them in a fee simple townhome project way back in 1983.