New Concrete without Vapor Barrier Question

[K10chase]

Hi everyone, I am looking for recommendations for a floor coating for my new concrete. I had been looking around at different options such as a polyurea like SPGX or Nohr-S for just a clear finish before I move things in after 30 days. I also considered just doing a surface sealer like ts210 or hd6600 for clear gloss/semigloss. The third option was ghostshield, which I liked the idea of, but was hoping to have some gloss on the floor, so it was not my top choice. The shop is about 1900 sqft, so budget is a limitation, as well. It was power troweled and relatively smooth. It will be used for automotive detailing, bodywork, and mechanic work with some welding and grinding.

Now here is my question. When it was poured, it was a last minute decision to not do a vapor barrier because of how sandy the soil is and we didn't think it needed it. The concrete guys actually had it laid out and decided it wasn't needed. I am now kind of kicking myself for this because it seems like I might not be able to do a surface floor coating in case the concrete moisture changes? I have read some people end up having coatings peel up from this so I was curious if this was true or if there was something I could put on the concrete first to try to limit moisture movement within the concrete. Any help would be appreciated as I am still waiting for another few weeks before I can put a coating down.

 

[LegacyIndustrial]

Florida is largely a sand-base. Water can be found 20' below the surface in Orlando.
We have little if any moisture issues with coatings due to the sand, it wicks away the moisture.

 

[K10chase]

That was what I was hoping, my soil type is ranging between 70-85% sand content and is very well drained so I was hoping that would have some benefit. The barn was built in 1986 and had fill in and around it initially, but I do not think that will have a huge effect on anything.

 

[ConCretin]

Vapor barriers aren't alway necessary. If your soil conditions don't require it, you can save some money and simplify the finishing process by skipping it. The trick is knowing when one is required before you pour. It's tough to put one in after the fact although there are topical vapor barrier products you can apply after the slab is placed if you do have an issue. Sounds like you'll be fine but I'm sure the pro's on here will tell you how to test the slab to be sure.

 

[LegacyIndustrial]

Vapor barriers aren't alway necessary. If your soil conditions don't require it, you can save some money and simplify the finishing process by skipping it. The trick is knowing when one is required before you pour. It's tough to put one in after the fact although there are topical vapor barrier products you can apply after the slab is placed if you do have an issue. Sounds like you'll be fine but I'm sure the pro's on here will tell you how to test the slab to be sure.

Yes Sir, make a test.