Help! Garage Floor Moisture

[wmblanken]

I've been planning a project to coat my garage for several months now. Have been researching epoxies, polyureas, etc and ready to go, but found an issue.

In one corner of my garage, a corner that is on the outside of the house (as opposed to connected to an internal wall) there is an area of moisture that appears whenever it rains. I am pretty sure its coming up through the slab (rather than down through the walls or seeping in under the sill plate). The more is rains, the larger it gets. If it does not rain for awhile it goes away. It's not a puddle, just a damp, dark spot about 3 ft square.

Obviously, I don't want to put a coating on top of this. Is there anything I can do to solve the problem? I am thinking in terms of something I can put on the floor to "seal" it or something? Or is that just not possible?

Ideas appreciated. Please let me know if more info is needed.

 

[Shea]

Have checked to make sure water drains away from the garage and does not pool next to it?

 

[LegacyIndustrial]

The type of moisture you are describing is NOT solvable with a coating/sealer.
As Shea mentioned, start looking for the disease.

 

[wmblanken]

that is what i thought on the sealer. we've had drainage "experts" out and they said that it looks like water is up against the foundation and seeping through to the garage slab somehow, but they cannot find the source. all the grading etc looks good, and the slab is two to 3 feet above grade, so its got them stumped. But its obviously coming from somewhere so they'd essentially need to dig everything up including a bunch of landscaping, open up the walls, etc. to find where its coming in. They actually recommended just leaving it as its not a ton of water and there don't seem to be any cracks in my garage floor. But that would mean no coating for me. And I guess the worrier in me says that it could be a symptom of a larger problem.

thanks for the help.