clarification on the layout of a 220kv multistorey substatio

huangyhg

clarification on the layout of a 220kv multistorey substatio
i'm working as a site engineer on a 220kv substation building. the building is coming up as a multistorey. now the situation is like this, i have the 220gis hall in the ground floor and directly on top of it the hvac machine room, with air handling units, chilled water pipes and pumps running everywhere. my floor finish is 75mm screed with a 5mm epoxy screed toping. the area of the room is over 280 square meters.
my question is, does this a/c machine room poses as a threat of dampness/wettness source for the 220gis or not. and if this is the case what is the best way to provid a water proof slab over that area
if the structure of the floor can handle it, you could put a vapor barrier 10 mil (us units) under another topping slab.  you could use a lighter weight fill material such as elastazill, and then a epoxy coat finish.  you will likely have to run the numbers to make sure that the structure will work with this addtitional load.
hope this was helpful.