In an earlier blog post I mentioned my preoccupation with expansion joints. These thin vertical  joints in the mosaic are prepared by using 1/16″ pin striping tape and thin rope to designate clean lines that are filled with a flexible caulk (instead of grout) to allow for small amounts of movement within the concrete. 

Soon after grouting , the rope used to protect each vertical expansion joint line is carefully removed and the gap is filled with the flexible caulk. We have installed 9 of these expansion joints that are now filled with caulk and nearly impossible to see in the finished mosaic mural.

There are four caulked expansion joints in the part of the mural where a crack in the concrete was repaired by Joe McCarty (www.joetile.com). Can you see them? (I can’t.)