Gnanchandra

We have to paint below ground concrete surfaces with Epoxy PAINT or Bituminous paint. The engineers says we can paint only after 30 days. What is the actual time gap required to paint on new concrete surfaces.
Any reference to international codes? We tell him only 7days are sufficient.

What is the international practice for such painting?

Thanks.

painterdude

there is no way the moisture will be out of contrete walls below grade in 7 days. The way to check moisture on concrete is to put plastic on the walls and seal the edges tightly(maybe several times) with tape. If there is any condensation on the plastic....it's still wet. Thats just the old fashioned way. I'm sure there are meters today that will measure moisture content. pd

painter213

It is prefered to let the concrete cure for at least 28 days. If there are curing agents used, you can get on sooner. You can check out the Society for Protective Coatings SSPC-PA 7 Specification for Applying Thin Film Coatings to Concrete for further information. Also check out the ACI International Standards for more standards available. Also, as far as test methods go, you can check out ASTM D4263. This the Plastic Sheet Test Method. This test only tells you the presence of moisture in the concrete. Pretty much ALL concrete has some moisture. For a detailed test, you will need a Quanative test to get the amount present. If the concrete is exposed on one side, then your not going to be trapping any moisture in place. It will have a way out, anyway. One thing is to make sure that you do the required surface prep. If you do not, then you can apply the best coating out there and it will not last. You can also check with the ICRI "International Concrete Repair Institute" for more information as well. There is a lot of information out there. Also, I would recommed to check with your coating supplier, to see what there requirements are for concrete application. Get a specification and follow it.

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Benny Abbott
Abbott Consulting and Coating Inspections
E-Mail: babbott@abbottcoatinginspections.com
Phone: (205-717-0292)

MALCO.New.York

WRONG. PERIOD. 30 days is the accepted allotment of cure time. Actually it takes a couplea years for a slab to TRULY "Cure".

Especially with a "Below Grade" pour.

I know bunk about the Science of Crete, but I do know that which I share.

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Ultimate Wisdom---------
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Chris Johnson

First off concrete cure is a loose term. In the concrete business we base what strength we can reach in 28 days, this is the industry standard since Christ was a cowboy. Concrete takes longer to cure than a couple years is dependant on several factors, exposed concrete continually cures till it starts deteriorating, that time frame varies by all sorts of factors none of which can be answered quickly or properly without science getting involved and exposure and placement and location and weather factors, etc.

For a below grade application using a bituthane type product application after 7 days is generally acceptable, depending on weather conditions the wall has received since the initial pour. It's one of those things that requires an experience concrete guy to look at the wall and say either yes or no you can apply the product now. I have applied bituthane the following day in certain climates without issue and have also done projects where I had to wait over 2 weeks.

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Chris

capital city

All you have to do is go to the paint store and pick up a gallon of paint that u plan to use. It will tell you how long you need to wait or all warranties are void. Plus you have the engineers right there telling you the facts just open your ears.