Epoxy on Soft Concrete

[tonetone]

Hi Guys,

I'm new to this and I believe someone has already asked this.

I am planning to have Epoxy professionally done on my current floor which is a really soft concrete (makes mark when i put a screwdriver to it, gets sandy when i run my foot over it).

I was doubting it (still now), however my contractor told me he will be applying a commercial grade primer that will harden the floor, therefore allowing the epoxy to stick. I just wanted to know if this is possible or if anyone else has experienced this.

I am scheduled to have my floors done in 2 days and was hoping to get some feedback before I spent a few thousand. Please email me at [email protected] Thank you.

 

[dcs Inc]

This can be a slippery slope. If only the surface is soft then a good grind to a solid base would eliminate problems down the road. Often concrete finishers will bless the surface with water to get the surface closed up. This weakens the top of the concrete and creates a soft surface. If the concrete is soft threw out then I wouldn't apply epoxy to it. The epoxy will hold up but what will happen a delamination of the concrete itself taking the epoxy with it. The epoxy applicator is off the hook because his application didn't fail, your concrete did.

There are companies out there that can test your concrete and give you a report on the condition, compressive strength, density.. all that stuff you really should know before having the epoxy applied on a questionable slab. Not sure of the costs to have these tests done. Your local concrete supplier should be able to get you into contact with the right people.

 

[pauloman]

the quick and dirty attempted fix is a solvent thinned epoxy (primer) that will hopefullly soak down enough to give you a solid surface.

The professional approach would be 2 inches of fresh cement on top.

- I would proceed slowly. Probably look at some sort of mat or rug instead of paint or epoxy in your case.

 

[Garage Flooring]

This can be a slippery slope. If only the surface is soft then a good grind to a solid base would eliminate problems down the road. Often concrete finishers will bless the surface with water to get the surface closed up. This weakens the top of the concrete and creates a soft surface. If the concrete is soft threw out then I wouldn't apply epoxy to it. The epoxy will hold up but what will happen a delamination of the concrete itself taking the epoxy with it. The epoxy applicator is off the hook because his application didn't fail, your concrete did.

There are companies out there that can test your concrete and give you a report on the condition, compressive strength, density.. all that stuff you really should know before having the epoxy applied on a questionable slab. Not sure of the costs to have these tests done. Your local concrete supplier should be able to get you into contact with the right people.

+1 for testing the concrete. If it is soft, go with a good alternative to epoxy

 

[Edger]

If you do not give the floor any heavy treatment it will probably be OK, but if you drop anything on it or wheel a heavy load over it with small, hard wheels the concrete will crush and powder underneath the epoxy coating and the epoxy will form a bubble which will eventually break and appear to be peeling.

Using a densifier before coating would be the way to go after grinding back to the aggregate. The primer is almost unnecessary because the epoxy will soak into soft concrete very easily on the first coat, especially if thinned a little.

 

[Tricon]

Sounds like RaceDeck is in your future!

 

[Shea]

Actually, a screwdriver test is the first method that is used to determine if the strength of concrete is suspect. If it is easily scratched or gouged, then that is not good. While it is considered crude science, it definitely means that the surface is soft if not the rest of the slab. I have to agree that if the epoxy is installed on soft concrete, the surface underneath the epoxy WILL break down over time depending on use.

If you are still considering it, I would at least ask your contractor to grind a test area first. If that reveals a much harder surface then you should be fine. If not, then you have other options such as tile.