I walked around barefoot on my travertine deck on 97+F days in Katy, TX quite frequently. It's not hot whatsoever. My deck gets full sun from 6:30AM to 7PM at night. One thing to remember is that darker travertine tiles will retain more heat than ivory one I have. Are you going to use that antico onyx everywhere? It's quite darker brown than ivory, so it might get hotter than my deck. Something to consider.
My PB used the same travertine (1.5" thick) for my existing concrete deck and the sand based "new" deck area. It's seamless and flows so much better this way.
Regarding the concern of raising the existing deck by 2" (1.5" travertine+3/4" of sand base I think), I figured if my backyard gets flooded my deck would have 2" of extra height before it goes under the water.
If possible do the existing patio and the new deck together.
My PB used the same travertine (1.5" thick) for my existing concrete deck and the sand based "new" deck area. It's seamless and flows so much better this way.
Regarding the concern of raising the existing deck by 2" (1.5" travertine+3/4" of sand base I think), I figured if my backyard gets flooded my deck would have 2" of extra height before it goes under the water.
If possible do the existing patio and the new deck together.