No lies here, this is not fiction.

For a favor to a design firm, not local to NYC, I need input on use of
urethane grouts on a project. Looking for sources of reference. Need to locate
manufacturers of urethane grouts that would be appropriate for this
application. Need contact information with someone experienced in this
solution for this or similar problems.

Existing is a 12 story façade built in 1970's that consists of CMU with ¾"
travertine panels with 1/16" jointing. Stone panels are set 1-1/2" from the
CMU, forming a cavity by use of mortar spacer-stools and copper wires for
attachment. The problems are that the building leaks water, no vapor barrier,
and that with thermal movement the stones are cracking on edges as a result of
the thin joints.

Proposed solution is to cut the joints wider, which will destroy the copper
wire attachments, install stainless steel anchors with washers through the
face at four corners, and to inject a urethane grout into the cavity to
provide both adhesion to the travertine and a waterproof barrier behind it.

I'm concerned about the following issues. Weight of urethane grout deflecting,
and effect of newly created vapor barrier, on thin cross section of
travertine. Adhesion properties of urethane grouts to CMU and travertine.
Possibility of expansion of urethane grout blowing out the stone. Public
exposure to hazardous chemicals. Active facility cannot be shut down.

][<en Follett