Concrete Hardener Before Coating?

[ZenGorilla]

I have a 100 year old garage floor. I am about to fix a few cracks, then diamond grind it in preparation for some kind of top coat (epoxy? polyaspartic? both?).

Recently, I picked up an old piece of marmoleum that was just laying on the floor and there was moisture beneath it. The remnant was not covering any cracks. My thought is that I need to use a concrete hardener to minimize/prevent moisture from coming up through the floor.

My question is this: If I harden the concrete after I diamond grind it but before I put my finish on it, will that prevent the finish from bonding? Or if I don't harden the concrete and I put the finish on it, will the moisture that seeps up diminish the effectiveness of the finish?

To be clear, there has never been any standing water as a result of the seeping, just dampness.

Thanks ahead of time for any guidance that you can provide.

 

[LegacyIndustrial]

Zen:
Densifiers holding back moisture is a subjective discussion. Completely dependent on the density and porosity of the concrete, efficacy of the product, application, etc....

My advice would be to do an actual moisture test. See how the results are and take it from there. One option to consider is a Moisture Vapor Barrier Primer. Especially if placing high performance coatings on the floor.

Good luck!

 

[Garage Flooring]

I have a 100 year old garage floor. I am about to fix a few cracks, then diamond grind it in preparation for some kind of top coat (epoxy? polyaspartic? both?).

Recently, I picked up an old piece of marmoleum that was just laying on the floor and there was moisture beneath it. The remnant was not covering any cracks. My thought is that I need to use a concrete hardener to minimize/prevent moisture from coming up through the floor.

My question is this: If I harden the concrete after I diamond grind it but before I put my finish on it, will that prevent the finish from bonding? Or if I don't harden the concrete and I put the finish on it, will the moisture that seeps up diminish the effectiveness of the finish?

To be clear, there has never been any standing water as a result of the seeping, just dampness.

Thanks ahead of time for any guidance that you can provide.

Zen:
Densifiers holding back moisture is a subjective discussion. Completely dependent on the density and porosity of the concrete, efficacy of the product, application, etc....

My advice would be to do an actual moisture test. See how the results are and take it from there. One option to consider is a Moisture Vapor Barrier Primer. Especially if placing high-performance coatings on the floor.

Good luck!

Moisture issues before coating, do a moisture test, and apply to appropriate vapor barrier per the coatings company instructions.

In general, a densifier or even a densifier / selaer have no negative side waterproofing capabilities -- that is to say they don't technically prevent moisture from coming in from underneath. That said, a good densifier over good concrete will help some for floors that are not being coated.

It is not because they are waterproofing the floor but reducing moisture wicking as a 'side effect'