• 2 Vote(s) - 3 Average
  • 1
  • 2
  • 3
  • 4
  • 5
Adhesives and Moisture

#11
Not this board Ray, the other Ray. I am certain you know of him.

I am the question man, not the answer man. What I find is amusing that after all these years in the industry I've seen ppl...so called experts jump on any bandwagon manufactures design only to find out years later that opinion was a myth, destroyed by science. Failed floors blamed on installers by the landfill full all for not. How many lives and reputations destroyed by bad science manufactures bring to the table.

The biggest ones now are engineered wood delaminating due to low rh. And elevated moisture levels alone destroy floors.

I think the new one might be high rh in a slab destroys floors.

I have seen the pictures of men pulling a piece of flooring, and immediately placing their CME on the slab and calling it "failure due to elevated moisture levels". Seen it in reports. Men with no flooring installation background at all inspecting floors they no nothing about other than a multiple page exam. Disturbing!!

The inspection industry needs a total redo, no grandfathering and run out the brokers.

G'day
Reply

#12
Well, you know I'm a proponent of RH testing! But my scope is limited to homogenous floors and moisture sensitive flooring.

I have many times consulted on jobs where the flooring manufacturer rep cut open a floor and slapped his electrical impedance meter on the slab and told me and the owner "It's too high!"

I love messing with guys like that. What's too high?
"The moisture" they answer.
Really? What is it?
"It's at 5" they'll say.
5 what? is what I ask. Now they have no idea. They don't know what the '5' is. It sure isn't MVER.... But it's too high and they won't stick around to help solve the problem. And that is why I'm there, to determine the problem and resolve it.

I'm pushing for inspector certification. There are some small groups that self-certify and they may become recognized, but it would be great if CTL or someone would certify. I need to keep digging....
JD Grafton
Concrete Answers for Flooring Problems
[email protected]
Reply

#13
LOL exactly, I hear ya. As the moisture in the slab equilibriated after covering, if you open the slab up and throw your meter on it what is it going to read? DOH . Lets see, the impetance meter reads in percentages....percentages of what? Is it volume? Is it the percentage of the area of that the meter is currently reading?

I like Bob's question he presents to ppl on the stand. Where's the science behind what your presenting as evidence, who wrote it where is it to be found?

You two guys might get along some day.Rolleyes


http://www.tucsonazflooring.com
Reply

#14
I think I am going to get Wagner RapidRH Certiied. What the heck.

I am still looking for that scientific evidence that equilibrium of the slab creates more MVER. Anyone got that in a scientific document?
Reply

#15
Congrats Ernesto, we'll have to call you Sir Ernesto or something now! Big Grin

I don't have scientific testing, I would think CTL Labs would have it, there may be reference to it here in the training videos also.

I experience it every day, and can explain how it happens though!

CaCl tests only read the top 1/2" of concrete (technically it depends how porous the concrete is, but 1/2" is a good generalization).

If the top 1/2" is very dry, it will read low on an emissions test. If it is wet it will read higher.

Concrete dries from the top so the top is almost always drier than the bottom. There can be exceptions to this rule, such as a slab that has been flooded recently.

When a moisture vapor blocking product is placed on the slab, the higher level of moisture in the lower portion of the concrete naturally equalizes with the drier upper level of concrete. This causes the top of the concrete to become wetter than it was before.

In the field I see this when sheet vinyl is placed on a 'MVER dry' slab that is still green, or one that has no vapor retarder below it. Over time the flooring may fail and when new MVER tests are taken they are significantly higher than the initial tests. Taking good RH tests can indicate moisture within the slab that has the potential to cause future failures.
JD Grafton
Concrete Answers for Flooring Problems
[email protected]
Reply

#16
Yea yea yea, you know how to tow the party line doncha?

Here's a question for ya.

If the slab has a "barrier" under it so no moisture can get to it and the hvac has been running for lets say a couple years. Then why would the bottom not be dried out like the top? Smile

Here's another, If the cacl test is picking up mve from the 1/2 inch or two of the slab, then why is that rate going to go up if the slab equilibrates? Now I know what your going to say...because the rh in the slab equilibrates and the more rh that reaches the top there for in turn turns into mver right?

If yes show me the data!!!! LOL

Have you ever tested a slab with rh probes and cacl, then covered it in plastic then run both cacl tests and rh tests again in the same proximity?
Reply

#17
Ernesto, I will agree that over several years time of drying the bottom of a slab will be drier, but most likely not as dry as the top. Maybe, but most likely not. Moisture moves slowly through concrete, especially when there's not much of it.

Ernesto Wrote:If the slab has a "barrier" under it so no moisture can get to it and the hvac has been running for lets say a couple years. Then why would the bottom not be dried out like the top?

Here's another, If the cacl test is picking up mve from the 1/2 inch or two of the slab, then why is that rate going to go up if the slab equilibrates? Now I know what your going to say...because the rh in the slab equilibrates and the more rh that reaches the top there for in turn turns into mver right?

The moisture equilibrates in the slab, and the top of the slab becomes moister than it was. Wetter concrete has the potential to emit moisture at a higher rate.

And yes indeed I have tested slabs and seen MVER go up significantly as the moisture equilibrates.

As for data, what are you looking for? This is all I do, every day. I'm working on a slab right now that has documented MVER at 3.4lbs in 2008 with RH of 95%. Right now the slab reads 7.5lbs MVER and 93% RH.

Many times I am working on slabs that are poured in pan, so underground moisture is not an issue.

Did you take the RH course yet? Did you watch the videos? Everything is explained quite well in those great videos.
JD Grafton
Concrete Answers for Flooring Problems
[email protected]
Reply

#18
I've watched the videos three times.
Reply

#19
when using the tramex meter i know that 6 shows moisture but what are the other numbers? for example if you get a three reading what does it mean?
Reply

#20
Great Question!!

The Tramex CRH meter is also an electrical impedance meter, which is how you are using it when you place it on the slab and read the number 6.

Many times I have watched a flooring installer place an EI meter on a failing floor and tell me "It's 5, that's too high!"

I always ask, "5 what?" Invariably the answer is "I don't know but 5 is too much". Smile

And that is the big question.... What does it read? The EI meter reads the conduction of electricity through the slab. More water in the concrete will conduct electricity easier, and the reading should be higher. But the conductivity is also influenced by aggregate type, density, steel location, even mix water chemistry.

It is a rough guesstimate of slab moisture in the top horizon of the slab. I will use an EI meter to check around the slab to see if there are hot spots getting high readings, and place some of my Rapid RH probes in those areas. But I always sprinkle probes around to get a good overall picture of the true slab moisture potential.
JD Grafton
Concrete Answers for Flooring Problems
[email protected]
Reply


Possibly Related Threads...
Thread Author Replies Views Last Post
  Moisture going up Rubensgt40 3 1,593 07-05-2014, 03:18 AM
Last Post: Rubensgt40
  35-40 year old concrete with moisture problems Tscdad 13 7,412 05-19-2014, 10:55 AM
Last Post: eaadams
  Digital moisture meter QC worker 2 1,889 05-10-2014, 08:07 PM
Last Post: Rubensgt40
  Tandus removes moisture testing requirement eaadams 2 4,118 09-27-2013, 10:26 AM
Last Post: eaadams
  Carbide moisture testing CC Solutions 4 8,692 09-18-2012, 06:11 PM
Last Post: CC Solutions
  Old concrete slab moisture DeanC 23 50,609 12-15-2011, 01:20 AM
Last Post: foxgeorge
  Flooring Manufacturer Warrenty in Relation to Moisture mwoody 5 10,935 08-14-2011, 08:43 PM
Last Post: Ernesto
Sad Is there a way to measure moisture plus cold temperatures sort of like a heat index b Ronald Edberg 4 10,745 07-01-2011, 07:11 PM
Last Post: rthompson
  Concrete Moisture Control Systems BuilderPDX 8 16,865 06-09-2011, 06:09 AM
Last Post: CC Solutions
  The Moisture Webinar Ernesto 17 33,334 04-01-2011, 09:02 PM
Last Post: CC Solutions

Digg   Delicious   Reddit   Facebook   Twitter   StumbleUpon  


Users browsing this thread:
1 Guest(s)