Epoxy over 7 day old slab - Printable Version
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Epoxy over 7 day old slab - ec-Indy - 08-18-2011 03:08 PM
OK, guys. Thought I'd throw this out to you. I poured an interior 4" concrete slab and will be attempting to place a 100% solids epoxy flake system on it in 7-8 days. I used a high range water reducer with micro silica in the concrete mix. 6 Bag, gravel poured at about a 4" slump. I placed a 15 mil vapor barrier under the slab and taped all openings real well. Here's what I'm going to try, let me know what you think.
I will be spraying denatured alcohol on the concrete for 3 days before epoxy placement to "help" pull out surface moisture so the slab can hydrate quicker. I will be applying 2 coats of a water based epoxy vapor barrier primer that's "suppose" to suppress up to 12 lbs. pressure.
I finished the concrete with an open float finish to not to trap moisture. I will be either spiral grinding or maybe even shot blast the surface before I apply the vapor barrier epoxy. I will be doing a RH test before I start. Am I pi$$ing in the wind and do you have any other suggestions? thank you in advance. gene
RE: Epoxy over 7 day old slab - Ernesto - 08-18-2011 07:30 PM
Well I have no answer for you but I have never heard of the alcohol treatment. Sounds interesting. Is this a standard treatment or something you just thought up?
RE: Epoxy over 7 day old slab - ec-Indy - 08-18-2011 10:29 PM
If the slab is open, it will pull moisture out of the surface. Doesn't do much for moisture in the slab. My theory is removing the moisture near the surface will speed the process. gene
RE: Epoxy over 7 day old slab - CC Solutions - 08-19-2011 07:07 AM
My questions: What are the warranty requirements of the epoxy manufacturer?
What is the alkalinity limit of the barrier primer (fresh concrete is extremely alkaline)
How much money are you willing to lose if the job fails?
I mitigate slabs like this daily, and it has been my experience that there are several products out there that CAN handle these conditions for a lifetime, and thousands of products that can't. The ones that can handle high alkalinity and moisture are not suitable for any other purpose. They are not wear layers, not pretty, they do one job only.
Yes, your slab will be ultra wet and highly alkaline. If you can meet all the warranty requirements of the manufacturer then you should be protected if the thing does blow up, if not, I'd think of making changes ahead of the installation.
Oh, one last point (and a favorite of mine ) read the manufacturer's warranty closely. My prior employer was burned by a product that promised it would work under the worst circumstances, and we used it on several projects with great results. But when we had a failure that should have been covered by the manufacturer, the company pointed out the fine print... They were only liable for replacing the product, nothing else, no implied warranty, no damages, no replacing the flooring that had to come out. We repaired a $350,000 floor and they offered a $500 bucket of epoxy as their sole involvement. I guess my employer was so big they thought they could ignore the fine print, but it turned out they couldn't, and we all learned a valuable lesson. Warranties protect the manufacturer, NOT the customer.
RE: Epoxy over 7 day old slab - Ernesto - 08-19-2011 08:00 PM
(08-19-2011 07:07 AM)CC Solutions Wrote: Oh, one last point (and a favorite of mine ) read the manufacturer's warranty closely. My prior employer was burned by a product that promised it would work under the worst circumstances, and we used it on several projects with great results. But when we had a failure that should have been covered by the manufacturer, the company pointed out the fine print... They were only liable for replacing the product, nothing else, no implied warranty, no damages, no replacing the flooring that had to come out. We repaired a $350,000 floor and they offered a $500 bucket of epoxy as their sole involvement. I guess my employer was so big they thought they could ignore the fine print, but it turned out they couldn't, and we all learned a valuable lesson. Warranties protect the manufacturer, NOT the customer.
Good point JD. Lots of those off the shelf products you speak of avaliable to installers and contractors have that same exact warranty writtin in there. I can think of only one off hand that will replace the floor and labor and their own product. But brother, you should read Franklins requirements. Ya better have your I's dotted and T's crossed plus fully documented.
RE: Epoxy over 7 day old slab - CC Solutions - 08-19-2011 08:21 PM
I can think of 4 I trust for warranty. These four also have excellent technical departments. I have worked on projects where I have had to call the tech department of a less-than-4-star company and I was shocked at the unprofessionalism (7!!) that I heard...
The big companies are expensive, but not as expensive as crossing your fingers....
RE: Epoxy over 7 day old slab - ec-Indy - 08-20-2011 12:48 PM
Well I checked the floor today. The carpenter is running 2 days behind so that gives me a little more open time. I installed one of the tests I will be doing to see the vapor emissions. I also tested the concretes pH level. It came out at 9.5. I will be doing the rapid RH test on it as soon as it arrives.
After checking a little more on my mix design, I'm finding that the dry shrinkage is reduced as well as lower permeability. It also has suppressed alkali and silica reactions and nearly no calcium hydroxides. The rapid drying and cement hydration will "hopefully" be in my favor. The tests will tell me a lot and I will report those findings on here.
As far as product warranties and such, yes, materials only. The vapor barrier epoxy which I'll use as a primer coat is suppose to hold back 12 -15 pounds of pressure. I don't like pushing those numbers. I was just wondering what else I should be looking out for. I think using my shot blast machine will open the surface and give the primer coat a good grab and saturation.
Humidity levels have been kept to around 52% which should help. It seems this specialty mix is becoming popular with the high performance concrete installers. If you guys have any other suggestions, please throw them out. Just trying to cover all my bases.
RE: Epoxy over 7 day old slab - CC Solutions - 08-20-2011 09:47 PM
EC, you sound like a pretty smart fella...
You take an MVER using F1869 on your burned-black, hard surface, compacted concrete. You get a reading of 5lbs. Now to increase your primer bond to the concrete you blast the surface with your handy-dandy blaster machine.
What is the MVER AFTER you blast? You have ripped apart a perfectly good suppression barrier of a tightly bound cement matrix... Your MVER will go through the roof! And if you put a tight vapor retarding floor on the concrete surface, you will suppress moisture that would have dissipated naturally and as the concrete moisture redistributes and equilibrates through the depth of the slab the MVER can definitely become significant.
I have worked on many slabs that were treated when they were 7 pound slabs and after a failure they were tested to be 12 pound slabs. Or the alkalinity is high and the warranty doesn't cover that!
You know you can go pick up some Ardex MC Rapid for less than $1/sf and have a bulletproof warranty.... Why mess around with a spray and pray or sweep and roll on product with a terrible warranty???
I just don't understand why installers are rolling the dice with any installation when the perfect system is really quite reasonable....
RE: Epoxy over 7 day old slab - ec-Indy - 08-21-2011 02:26 AM
Good point there JD, I appreciate the reply. As far as a burned in glazed finish, I'd agree. That was why I finished the slab with an open float finish. As far as ardex's limited warranties, I quickly looked over them. Lot's of holes and dances you have to go through. What does it take to become an "ARDEX LevelMaster Elite Installer"? I'll look into that product a little deeper to see why it's the bestest. Thanks
As far as being a smart fella, just gathering information to make a educated decision. I've been a decorative concrete contractor for 35 years and have learned how to read through the smoke and mirrors of manufactures. I can also understand their liabilities. If there are other product lines out there that I can compare, please let me know. Oh, I'm also looking at Koster's product lines too. gene
RE: Epoxy over 7 day old slab - CC Solutions - 08-21-2011 08:06 AM
Koster and Ardex are my two main products. I did a Koster job Thursday and an Ardex job Saturday. I had a chance to use the newish Ardex MC Rapid. Weird stuff for sure. Filled with metallic specs which are supposed to help provide the barrier layer.
It's funny how Ardex and Koster approach the same goal from completely different perspectives. Both companies are excellent. I have not used Aquafin but it seems to be a solid product with a good reputation.
To be a Levelmaster Elite, you must be recommended by an Ardex rep and pass their tests. They don't let many become Elite, but anyone can buy Ardex products. Koster will not sell products to the public, you must go through their training.