This is my first time posting so bear with me. I am redoing my backyard with 3000 sf of travertine I am installing a 8x10 fiberglass jacuzzi 2 feet above 18x36 viny pool. I was going to build up edge of jacuzzi with travertine stone to create overflow waterfall that went into pool. I know they make the jacuzzi tubs that have this already but I am a vain Long Islander and didn't want to go with the ugly white overflow lip. Problem occurred when I set my jacuzzi (which is plumbed with skimmer) and sat in the jacuzzi, I realized that if I added 4 1/2 more inches to top of tub (to create overflow) my face would be half way under water when I have the overflow on. My two options are get the spa pillows that would raise seats by 4 1/2 inches or cut into fiberglass and create waterfall. If I cut into fiberglass and build a shelf how would I then waterproof that joint then install stone over top? Any suggestions, comments, criticism would be welcome.