Hi

I have a detached garage with a studio attached to. Every time I walk in the garage it smells moist. I have toughed sheetrock walls they are not wet. Yes it is a slab concrete
With many crakes every where.
The moister smell is most in garage and some in attached studio.

What do you think it is going on, and what are your suggestion and commons?

THANK YOU

Concrete is pourous , water will leach readily through it and evaporate into the rooms.
You can apply clear sealers to a concrete floor easily. Several coats of sealer will drastically reduce the water vapor in that part of the building.