Want to waterproof foundation around cool room
Bituthane membrane (spelling could be off) membrane is used on foam ICFs, and I think it would work on clean concrete. If you use it, install it VERTICALLY. It is called "female dog-athane" because it sticks to most anything. On all-weather wood, I used a special tar-type coating, covered w/ black visqueen, 30 yrs ago and it has worked fine. IMO, the most important thing it to seriously slope the ground away from the structure, have good roof overhands, gutters, etc.