From: "Haan, Scott M." <HaanSM(--nospam--at)ci.anchorage.ak.us>
Date: Sat, 9 Feb 2002 17:09:28 -0900
wrong on a few points about the IBC in my diatribe about design of portions
and combination of R's on the same axis . IBC 1617.6.2 & IBC
1617.6.3 allows you to vary R's from grid to grid for houses and duplexes.
Also IBC 2308.12 says you can design a portion of an unusual
house. Perhaps these provisions are the brainchild of nihilist
iconoclastic enemies of engineered residential construction.
for enlightening me. In any case I do not see why a plan
reviewer would not allow someone to use a more current structural code
Scott: Here in Southern California we use
an exception to the UBC. 1999 SEA California Recommended
Lateral Force Requirements and Commentary
Sec 105.4.4 Combinations
Along the Same Axes
Exception: For light frame buildings in occupancy
groups 4 & 5 and of two stories or less in height, the lateral force
resisting elements are permitted to be designed using the least value of R for
the different structural systems found on each independent line of resistance.
The value of R used for the design of diaphragms for a given direction
of loading in such structures shall not be greater than the least value used
for any of the systems in that same direction.
Johnson & Nielsen Associates Palm Springs, CA