update: no shrinking --
I got a nice email from the Engineering Manager of Icynene with a copy of a letter from a Professional Engineer who inspected the foam on one of the Icynene manufacturing plants after 8y of service = no cracking evidenced -- no reaction with the galvanized metal onto which Icynene was sprayed -- the Icynene was overcoated with a fireproofing.

The Mgr stated that Icynene has been in use for 19y.

[Edited by cem-bsee on 08-30-2005 at 06:37 PM]