> Should I use some glass cloth or matting between the deck and hall
> to help fill the voids along with epoxie?

Glass cloth is rather expensive to use for filling voids. Buy some silica fume or microballoons to thicken your epoxy. I also read on someone's homepage about using fiberglass insulation as a void filler. He was building a sailboat and just used the regular pink Owens Corning fiberglass insulation. He'd just pull off a chunk, stuff it into a void, and then saturate it with epoxy. I remember him saying something about it turning from pink to bright red when it was saturated. Not that this will be any significant problem, as I assume you're painting it anyway.

good luck, Shawn