In a message dated 99-11-14 00:38:03 EST, you write:

>
>this is something to think about also in terms of expansion and contraction
>of the structural steel. If it is to close to the back of the stone , or
>imbeded into it, there can be alot of stress. this would be telegraphed at
>the weakest point ie thinest stones.
>---
Many Thanks to all those who responded to this querry; Although the steel is
not rusting; it seems the corners and the spandrels to be the most
problematic regarding the horizontal cracking of the thin stones.; I need to
do a head count to see if the sun side of the building is more affective; but
I beleve it is.The statement above is starting to ring true regarding
conditions.Without running afoul of the Conservator (who is nationally known
and I have alot of respect for) and second guessing his methods; it seems
thin veneer stones of 4" should be pretty independent of the structual
steel;but what would that look like if the back up brick work was tight into
the steel? were going back with traditional  lime mortar which should help
alot; the key here may be the anchoring system which is still in flux as
conditions become more apparent, and more stone is removed.Other conditions
such as failed pointing and internal drains abound, but I haven't seen any
real water damage per se; most of that is localized and obvious..Thanks for
the feedback; its interesting; does structual steel uniformly expand and
contract no matter what is its height and mass?(400' )...more later Best
Michael