Prep for old concrete, Need industry advice.

[Noob Installer]

Hello everyone.

Currently moving into the flooring industry, After 12 months of full time working for a large scale flooring company. Also many years in the waterproofing industry, I am not completely jumping into the deep end with my last breath. Though am fast learning where my lack of knowledge in this game, can be costly.

Well after talking to new suppliers and being told the sale pitch from them, i put my faith in one and went down the marketing track of garage resurfacing. After a few successful jobs all was looking on the up.

Though a few weeks after completing a job, i receive a phone call from the client. The issue that we where faced with was in my view two fold. 1, the top coat has discolored to some degree. This i put down to a high silicone/OTHER in the Tyre that is causing this. This was explained in full before the acceptance of the job. So to both of our displeasure we would live with this. 2nd in places the coating had delimited from the substrate, it had peeled off from under the tires. since the concrete was soft and primer coats had not penetrated as deeply as lead to believe, it had sheered the concrete substrate with concrete still attached to the epoxy that had been ripped off.

So its at this point that i tell the client that i will correct the garage, and take any extra necessary steeps involved to make it right. So my brother and myself headed there today and ground the concrete with a 30/40 metal bond and applied densi proof (moisture fix) this product is a concrete densifier that should help purge contamination from the substrate. The spots where the tyres sat did have porosity to them though may not have been to the same degree of the rest of the slab. Though after application of the densifier we noticed that these sections seamed to repel the densifier or where rapidly purging contamination from the substrate. I am at a place now where my concerns about silicone remaining in the concrete where discussed with the supplier and was told that this product would fix and issuers. until i go back tomorrow i will not know for sure that this is the case or not. My question is what is the best practice for dealing with contamination leaching from tires bearing in mind that is concrete has been initially ground and now today a heavy coating removal grind and finishing grind so there has been a lot of concrete removed. Is there a product that can be applied to purge this or is it best to look at cutting this out and placing a self level into the holes.

Aready into this job for a loss of over 1,5k so dont want to have a recall because a local supplier is selling sunshine and ******** instead of what i need.

Thanks

 

[LegacyIndustrial]

Silicone contaminants need to be ground out until gone. The areas ground can be filled back in with a mixture of solids epoxy and fine silica sand, pre-mixed and/or broadcasted.

I would do a simple water test to make sure they are all out.

Adding densifier makes the floor more "dense" and less likely to allow anything to penetrate.

I would have walked from heavy contamination, it's not worth the head-aches. Even if the customer agrees to the risk. He will never be happy when the coating fails.


Lastly, you mentioned the concrete coming up with the coating. Did you grind the floor or acid etch? A good grinding would have revealed weak areas and may have spared you that aggravation.

If you did a good job grinding and it still popped then that is a weak substrate and not a coating issue.

 

[Noob Installer]

The initial coating had worn through in places allowing this silicone? to drive DEEP into the concrete. Other than the the old acrylic coating was showing age though not heavy contaminated. It was just a oversight on my part about tires leaching this deep.

The concrete is on the weaker side though not incredibly soft. The initial grind was done with 30/40 grit metals medium bound. Suspected it was lightly rained on before initial setting up. So i gave it a good grind to expose a fair amount of the aggregate. And as you could imaging the slab is very porous, Also thinned the 100% solids epoxy via 15% for the initial coat.

After looking at the failed job i though, there would be the need to thin the product well beyond the 15% to allow for deeper penetration. Though talking to the supplier about this, they suggested that this is not a desirable thing to do (even though i have thinned the ****** out of Polly's before near 90%, all with good results). The best answer was to density, as this will allow a deeper penetration (Still don't see it though) and has the ability to drive (wax, bodily fluids, oils etc. It says this on the label also) out of the concrete.

So the plan is return tomorrow and sand the floor as recommended with a 80 grit paper and wash the dust. I think its about this point that i will need to cut out the silicone patches. I have both ardex k15 and epoxy/silica sand on hand. though because the floor will be wet at some point in the morning, i am thinking that the best option would be diamond cut 10mm down and jack out the rest and use the k15 and a quick sand over before the 1st coat.

oh well lesson learned, there is no magical **** remover for concrete. so cheek well where especially where tires sit.