Outdoor wood fireplace

[Tem670]

Building a kiva style fireplace on my patio and was wond er ing if the castable refractory cement formula I've seen on here is weatherproof? I have a chicken wire form. Going to put 1/2" ceramic blanket over the whole thing then use somthing to make the blanket ridged. Then coat the outside with either the castable refractory or stucco. Once that is dry I plan on using the castable refractory on the inside pushed into the chickenwire. Sound like a solid plan? Is the castable weatherproof? Last thing, have any of you ever put rods of heat resistant glass through the walls so the flame would make them twinkle?