RH Testing Thick Slabs - Printable Version
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RE: RH Testing Thick Slabs - Ernesto - 10-24-2012 07:44 AM
(10-14-2012 09:55 AM)CC Solutions Wrote: Being that slabs dry to the top, you could drill down until you hit a point that exceeds the maximum level of RH and stop there.
On the other hand, if you do not drill down to the required depth, and your reading is low, your just wasting your time and a sensor.
RE: RH Testing Thick Slabs - rapidrhrep - 10-24-2012 08:08 AM
Another thing to keep in mind with all of this is that many experts will tell you that any slab in excess of 12" many never dry naturally to an acceptable level for finished floor products. Dimensionally, this is why the Rapid RH is the size it is i.e. it can do 40% of a 12" slab. This being said, this is why many people do as is being spoken here, they do the max depth they comfortably can with the Rapid RH. I can tell you, I have had people who have gone to the extremes and drill, clean, and insert deeper than that. Human creativity never ceases to amaze me.
RE: RH Testing Thick Slabs - CCR - 11-20-2012 03:18 PM
THICK SLAB UPDATE:
Called back 2 weeks ago to get new readings. Guess what? Bingo!!! They're still in the mid to upper 90s. At this point, the manufacturer (or someone) had approved the use of a well known epoxy-based mitigation, and I assume they will be moving ahead with prep and application...wrong!
So they have the installer place 3 Cal. Clhor. kits in a 8,000+ sf area and they get levels of 2-3 lbs. Don't know if they even bothered grinding this black, slick, hard, power trowled surface.
Now they're going to shot blast the surface and wait. Hope they plan on being there awhile because that slab is never going to dry. But why take my word for it?
But this is what kind of amazed me...the GC said that the Wagner RH tended to provide "conservative readings", meaning (to me), that they were purposely calibrated to provide high readings. I responded that doing so would not only be unethical on Wagner's part, but would make thousands of tests invalid by ASTM standards. The subject stopped there.
People never cease to amaze me.
RE: RH Testing Thick Slabs - CC Solutions - 11-20-2012 03:28 PM
Opening the surface will promote drying. Instead of taking about 4 years to dry, that slab could be dry in one year now if conditions are perfect!!!
The low CaCl readings on WET slabs are EXACTLY why 1869 was changed, and 90% of the reason the flooring industry is struggling now. Sure that glass finish is allowing very little vapor out, but the slab is a time bomb waiting to ruin some installer's life!
And I know it's not porous... What do the installation instructions say about installing over a non-porous substrate? Do installers follow those instructions? Not likely.
Low VOC adhesives are just part of the new issues we face. How about ginormous power trowel finishing machines???
RE: RH Testing Thick Slabs - CCR - 11-20-2012 03:43 PM
The slab is 19 months old, and it will never, ever dry. I keep telling them this and they won't accept it. They're installing a static disipating, heat welded floor made by a well known manufacturer who is known to make premium, yet tempermental floor coverings.
They have a very good sf price for prep and application of the moisture system but don't want to spend the money.
Right now, I blame the architect AND the GC for not knowing enough about concrete to have 1). specified a more open, porous finish and 2). not including a contingency spec and price for a moisture mitigation system.
RE: RH Testing Thick Slabs - CC Solutions - 11-20-2012 05:21 PM
I agree the architect and the GC should have known from the get-go that the floor had to have good conditions to dry. Then when they burned the snot out of it they should have known for sure it wasn't going to dry unless it was opened up so it could breathe.
The truth is, I bet they are both shaking their head blaming the flooring installer for the problem....
And what is the first letter of the flooring manufacturer's name?
RE: RH Testing Thick Slabs - eaadams - 11-20-2012 05:26 PM
AAAAAnyones guess, TTTTTsk TTTTTsk on those who guees wrong
RE: RH Testing Thick Slabs - CC Solutions - 11-20-2012 05:30 PM
Nope... CCR PM'd me... Your guess is way out in left field....
The slab must be cast in place, so I assume it can dry from below....
RE: RH Testing Thick Slabs - CCR - 11-20-2012 05:33 PM
Yup. Isolated and from surrounding slabs and
engineered to take extra heavy loads.
RE: RH Testing Thick Slabs - CC Solutions - 11-20-2012 05:35 PM
Heavy loads = lots of stress on that floor system.... No time for a weak substrate!