You're fired!

In searching for some material on fireblocking, we ran across this thread on the DIY Chatroom.  Indispensible material.  This is generally the bane of do-it-yourselfers and code officials alike.

http://www.diychatroom.com/f98/how-fireblock-framing-37190/

Istockhouseplans is currently working on trying to fireblock a double 2x4 common wall with raised heel trusses.  We'd like to rock the wall all the way up and then hang the trusses but are unsure that the hanger would achieve strength through two layers of 5/8" type X drywall.  A more viable option would be to nail a 2x4 ledger through the sheetrock into the walls studs.  This would require 1.5" + 5/8" + 5/8" + 1" embedment = 3.75" nails.  While 18d nails might not be common, this is going to require a bunch of hand driven 20d nails.   Those won't exactly fit into a power nailer.  The other option is multiple 2x16 blocking between trusses.  Not really an option though.  Maybe stacking 2 pieces of 4x8 would do it?  Does anybody have input?