pole building concrete sealant?

[1990dtgl98]

Hey everyone! New here but already getting a lot of great ideas.

I bought a house in 2019 that I mainly bought for the pole building. 30x70 with 10' ceilings. One portion was 30x40, then a 30x30 was added 3 years later (so its esentially 2 interiors separated with a wall).

Metal interior walls, insulated, lots of lighting.

I have a bunch of toys (classic cars, boat, etc.) and the past 2 years I noticed the building is almost too well sealed. 3 seasons I have 90% humidity and occasionally its so h umid it drips off the ceiling. I notice a fine mold under the cars that sit for a little bit.

When I drilled for my lift I didn't see any plastic under the concrete as a moisture barrier.

I was just curious if there's anything that would seal the concrete to reduce some of the moisture and humidity in the building? I have a split unit ac on the one side but it's insulated well enough it hardly runs in the summertime. As a result I run 2 dehumidifiers in the shop but that ***** down some serious energy.

I don't need fancy (though I will do it if necessary) as I usually, weld, grind, etc. Is there anything that could help?

Thanks in advance!