05-05-2011, 12:11 PM
I know a couple of us are on the LinkedIn Group discussion about RH probes and Bob and I are having a cyber fist fight....
In a nutshell he's saying RH is an inaccurate and complicated method of determining free moisture in concrete, and in fact our RH probes are easily fooled by temperature, pore structure and natural concrete constituents!
I have asked him to put his money where his mouth is and guarantee a slab using CaCl and EI meters, and I'll provide the slab.
I think he just wants to sound like he knows something and comes up with these cotton balls in jars and wood chip sorptive scenarios for museum curators that don't amount to a hill of beans in the concrete world.
I told him we don't put floors over jars of cotton balls....
I've been wondering if I need a LinkedIN account....
Congrats to our newest Concrete Guru!!!!
Guru Guru Guru!
Uh, I don't think Bob wants to be here. Your so annoying.
Yea, you want me to send you my copy of Gorans book? The one you made fun of? The one person who Howard Kanare went to to learn insitu from hee hee. FOGETABOUTIT LOL Get yer own. I'd bet no one over there has even read it, cept for Howard who is lurking.
Oh if I could only copy and paste the section about...well never mind it is to much to write. But it all is making sense! There's sooo much in there that you do not hear about from the movers and shakers.
I'd love to see you guys in court though.
Is gorans the Swedish thing?
Stephan, I'll get Goran's book.
My point is the industry people I work with are very consistent and trust the Wagner Rapid RH. We base our work on its results day in and day out. You can't do that with CaCl. You don't know what you have with a CaCl test! Wagner has proved MVER is flawed, Howard has proved it, Suprenant has proved it, Craig scoffs at it, I mean come on! You can watch CaCl fail in front of your eyes!
And that was my challenge to Bob, the biggest promoter of MVER testing and RELYING solely on MVER testing to determine if a slab is ready for flooring.... I have several slabs that read low MVER but ultra high RH and nobody in their right mind would put a rubber floor on them, yet he espouses complete reliance on MVER and bashed the RH test as voodoo.
Then when his slabs fail he says it's because of condensation at the time of glue installation. Get real.
05-06-2011, 05:08 PM
(This post was last modified: 05-06-2011, 06:57 PM by Ernesto.)
First off dew point is a big issue out there and has been one for a long long time. Most people have no clue about dew point and how it works and how it affects flooring or even how to detect it. It's one of those mystical things of nature. I had a link to a video where a scientist explains in with a bottle of water and ice. But then you probably would not like that type of explanation. lol
Also Bob is correct in that dew point is ALWAYS misdiagnosed as a MVER issue. Do installers carry around thermo-hygrometers and a laser infrared thermometer? No...but I do.
Like I said before I am a pessimist when it comes to new things, new methods. I don't believe Bob relies strictly on CaCl and neither do I. And I have never had a flooring failure in the 35 years I have been installing. Cept for that one vinyl floor that had the white patch under it that discolored...but heck, that was before anyone realized the issue with white patching compounds. Prolly before you ever smelled a wet slab. You may have been in diapers back then for all I know.
I have relied on CaCl tests for many many years and never had a failure. Now I do both insitu and Cacl along with my CME and my thermo-hygrometer and my infrared thermometer. Insitu is just another tool.
I certainly am not going to rely exclusively on a F-2170 test thats for sure. It may tell me what lying down below, but it sure is not going to tell me whats going to emit from the slab. Or even it that rh number will equilibrate to the top for that matter.
Until the concrete people start being responsible for anything but a few cracks in the slab I guess it's up to me, to protect me.
If I put a moisture mitigation system on top of the slab, I have to know either the results from a Ca Cl test or in situ test. Most manufacturers tell you their product reduces emission in lbs as in CaCl If they do not say that, how do you know it is safe? Again, how do you know for sure if you do not test after the app? Oh but ASTM does not WANT YOU to test after the app? Is this a catch 22 story or what?
Do they say "This product reduces rh to ______ extent?. Is that a promise or a wish? What extent is that? Is there a number that goes with those top shelf mitigation systems that rely on insitu tests?
If we as a whole, in this industry, have to go out and bead blast every damn slab out there and app a over priced moisture mitigation system over it just to HOPE we are safe then there is something SERIOUSLY WRONG WITH THIS PICTURE!
And the concrete industry as a whole.
We have adhesives that stick tiles to space shuttle vehicles. But I'll be damned if we can get an adhesive to stick to some friggin concrete and block emissions IN TOTO.
Condensation is not an issue for me. I do carry a infrared thermometer and a small $100 pocket temp/RH reader. If the building has the HVAC running (which is a requirement for installing flooring) the slab will not be at dew point.
But of course I do not install flooring, I prep floors and install MMS. In many cases the HVAC is not on, but I must NOT install when the slab temp is rising or within 5 degrees of dew point. It's really quite simple.
I realize you have installed for 35 years, but in reality the first 20 were much different. We had adhesives that could glue (what did that guy say?) shrimp boats to the ocean floor. A good friend and colleague of mine says we could have cattails growing and put the vinyl down with no trouble. The new adhesives require different parameters.
The good MMS systems are testing to ASTM E96, and we're not going to verify that in the field. I don't test after installing an MMS, it doesn't really matter because I know the system I use, and the manufacturer puts a 10 or 15 year full system warranty on the floor. If it ever fails, it's covered.
It is NOT the concrete person's responsibility to lower the RH or emissions. They have no control over how long the slab cures, how much water is in it, how thick it is, when the HAVC is turned on, nothing!
I believe it is the flooring contractor's responsibility to determine if the slab is ready for the type of flooring being installed. If it isn't, he should bounce it back to the GC and let him get it in condition. It's no different than if the building was at 20 below zero and the flooring contractor had to say he couldn't install until the heat is on and the conditions are right.
I have a unique perspective on this because I have been on every side of the situation and know what each contractor, architect, owner and GC is up against. I also sit at the resolution table and dissect where the process failed and who is responsible. I have also taken control of slabs from design to flooring to service that were successful and continue to be successful. Low RH and low MVER IS POSSIBLE if the slab is designed well and taken care of for the next 3 - 6 months.
The WORST thing I see happening is contractors who say "I've been doing this for 50 years and I never have a problem so this is all someone else's problem!!" If it's a flooring contractor he's right, it isn't his problem but he should be testing and may have to use different products he's not used to. The GC can't let rain flood his slab daily. The architect doesn't need a 6" slab on grade with 5500 psi, the concrete contractor can't burn the slab and then seal it with a silicate.
If you want a good dry slab the recipe starts with the design and ends with the flooring sub gluing to clean bare concrete. If you want to skip steps and do it the easy way, well a MMS can save the day. Like Leie said, you can ship UPS Ground and save the money, but if you want it Next Day Air, you have to pay the premium.
You ain't been me or a flooring installer/contractor. I've done prolly 90% of my jobs on concrete over 35 years with no failures. knock knock.
When I hear how Cacl tests are no good I look back and think. Maybe I was just lucky all those years. I have walked into houses and called it a wet slab. Totally righ using the testing methods of those days. It's easy to spot.
I've done the plastic. I've done the 1869 every which way, old way, new way. Ph tests, new CME meters, yup. Old meters you drove nails into the concrete to make contact with. Now I have a new tool, the rapid rh. Just one of many. But it ain;t the God send of the Universe.
Had a friend tell me today, insitu testing is just telling me the rh of the concrete surrounding that test point. Just like a CaCl test gives you a reading in that one area for the depth of a couple inches over 72 hours. Pretty much what Bob is trying to convey to you. I cannot divuldge his name but if you knew you would freak. He heads the most prestigious inspection entity known to the USA at this point in time.
Moisture testing is a crap shoot. I am just glad I do not count on one method on those HUGE commercial jobs that could really come back to bite yer azz.
Obviously you heard the guy on Linkedin say there are more and more failures in europe and they use what? Insitu. Finally someone confesses that insitu is not the cureall to moisture testing concrete.
And I hope you never do have a failure!!!
My background was to guarantee a floor for a lifetime. Not a year. Not two years. A LIFETIME. The testing we found was most accurate is the Rapid RH.
Now Nora rubber accepts NOTHING but the Rapid RH. And they will guarantee their floors using nothing but the Rapid RH. They will NOT ACCEPT any other in-situ probe. They have done extensive testing prior to taking such a strict stance. So if you install Nora rubber, you'll have to use Rapid RH probes if you want a warranty.
So when I say RH testing, I am specifically meaning Rapid RH, but I don't know if Wagner wants me talking that way outside of their own blogs.
So that's my position. I'll guarantee a slab using just the Rapid RH. That's how sure I am it works. My money, my company, my decision.