We are in the middle of a pool build. From the outset we told our builder we wanted travertine coping. Coping went in for the pool last week, and we are now being told that for the spa there is no travertine coping that is wide enough to cover the depth of the gunite (12") and stacked stone (stacked stone is 1/2 inch thick so not thick at all). We have single bullnose 12x24 travertine coping for the pool. The suggestion is that they will cut the travertine longways and make a double bullnose that way, leaving a grout seam along the surface of the spa. This is unacceptable to me, and we were never told that is is how they do travertine coping before today. I have seen countless images online of travertine coping on raised spas that do not have a seam on the travertine, so I know it is possible.

My question is does the gunite have to be 12" thick? Should the builder have made an accommodation when doing gunite to allow for extra depth for tile or stacked stone on outside of spa and still be able to use the 12x24" travertine?