BGE Cabinet Waterproofing

JPZATL82

Like many people in this forum, I am currently in the process of building a more permanent home for my BGE. After going through countless threads, we've come up with the design which will have a 2 inch concreter countertop, drawer, and cabinet for storage. The entire frame will ultimately be wrapped with reclaimed wood however, the interior frame is comprised with PT Fire Retardant wood. Yes, before people comment, I know wood is flammable but trust me, that has been taken into the design by making sure the space between the egg and any wood is more than enough distance so that there is little to no heat transfer. The egg will be sitting on a table nest which will rest on another slap of concrete.

None-the-less, my question is pertaining to water proofing so that the interior cabinet/drawers are as water tight as possible. I wanted to see if anyone has used applications like Mapelastic Aquadefense or RedGard before for any project like this. Both are exterior quality and I might be over thinking it but I want to make sure that all this effort in building a table will last as long as possible.

RRP

I know you are looking for a larger scale idea, but here is what I did that has made my drawer waterproof. 

See that drawer under my small egg? When I constructed the carcass for it out of treated wood I also then lined it internally with easy to bend aluminum flashing. On the back end there were two hidden seams which I overlapped the bent flashing and nailed them to the wood carcass after I had laid a bead of latex waterproof chalking. While hard rain will sometimes get in at the front of the drawer it does not get in the rest of it. 

JPZATL82

thats a great idea! thank you