With any pot call distance between the bottom of the striking surface to the top of the sound boards is crucial. I use the "double up" theory, whatever soundboard I use I start with doubling the thickness and laying it on the top of the pedestal. More then likely with ceramic, floor thickness would get you better results then experimenting with the soundboard distance, just use the standard, "double" theory and thin your floor to 3/16" if it is thicker it will create a shrill high pitched caller.