<![CDATA[Concrete Moisture Measurement Forums - All Forums]]> http://www.wagnermeters.com/concreteforum/ Thu, 17 May 2012 01:56:08 +0000 MyBB <![CDATA[Data Logger]]> http://www.wagnermeters.com/concreteforum/showthread.php?tid=276 Sat, 12 May 2012 00:02:29 +0000 http://www.wagnermeters.com/concreteforum/showthread.php?tid=276 <![CDATA[RH test results varying]]> http://www.wagnermeters.com/concreteforum/showthread.php?tid=275 Mon, 30 Apr 2012 21:20:25 +0000 http://www.wagnermeters.com/concreteforum/showthread.php?tid=275 Hello all,

I am new to the forum and am hoping to get some information/advice.

I am a project manager for a flooring firm in MN and am currently monitoring the RH on a slab for a project we will be installing VCT on.

I have 4 tests in currently, and they have been in for 3-1/2 weeks.

My question has to do with how much one can expect the RH readings to vary day to day? On Friday, my readings were 90%/96%/99%/88% and today, Monday, they were 93%/96%/99%/91%. So tests 1 and 4 both swung by 3 percentage points. I have some concerns that test #1 may have been compromised, as 2 weeks ago it went from 93 to 89 to 81 and then up to 93 all in a weeks time. Then it stayed at 93 for a week, then did the 88 to 91 swing over the weekend.

The adhesive we are using requires a 90% reading.

I will also note that the pH readings have been at between 7-7.5 the entire time. I also did one calcium chloride test near my RH test that has been reading 99% the entire time, and that came in at 6.87#/1000sf/24 hrs.

I know when I report the readings to the GC they are going to question why the readings were ok on Friday, but have now swung back up into the unacceptable range. If anyone knows were I can find more documented information on this I would appreciate that as well.

Thanks in advance! [/font]]]> Hello all,

I am new to the forum and am hoping to get some information/advice.

I am a project manager for a flooring firm in MN and am currently monitoring the RH on a slab for a project we will be installing VCT on.

I have 4 tests in currently, and they have been in for 3-1/2 weeks.

My question has to do with how much one can expect the RH readings to vary day to day? On Friday, my readings were 90%/96%/99%/88% and today, Monday, they were 93%/96%/99%/91%. So tests 1 and 4 both swung by 3 percentage points. I have some concerns that test #1 may have been compromised, as 2 weeks ago it went from 93 to 89 to 81 and then up to 93 all in a weeks time. Then it stayed at 93 for a week, then did the 88 to 91 swing over the weekend.

The adhesive we are using requires a 90% reading.

I will also note that the pH readings have been at between 7-7.5 the entire time. I also did one calcium chloride test near my RH test that has been reading 99% the entire time, and that came in at 6.87#/1000sf/24 hrs.

I know when I report the readings to the GC they are going to question why the readings were ok on Friday, but have now swung back up into the unacceptable range. If anyone knows were I can find more documented information on this I would appreciate that as well.

Thanks in advance! [/font]]]> <![CDATA[Dew Point Video and Orange Shirts]]> http://www.wagnermeters.com/concreteforum/showthread.php?tid=274 Tue, 24 Apr 2012 23:51:50 +0000 http://www.wagnermeters.com/concreteforum/showthread.php?tid=274
Why Concrete Dew Point is Important in Flooring Installations

http://www.youtube.com/watch?v=NZ4Heg17H...ure=relmfu]]>
Why Concrete Dew Point is Important in Flooring Installations

http://www.youtube.com/watch?v=NZ4Heg17H...ure=relmfu]]> <![CDATA[Bad Easy Reader?]]> http://www.wagnermeters.com/concreteforum/showthread.php?tid=263 Sun, 15 Apr 2012 01:46:19 +0000 http://www.wagnermeters.com/concreteforum/showthread.php?tid=263
I took readings approximately 1 day, 3 days and now a few weeks after installing the sensors. They've all came back at 99%. It is known to all involved that the slab is fairly wet.

The contractor had the vct contractor perform some relative humidity tests in the same area that my tests are in. He is getting readings in the mid 80's.

I went back to the site today and took readings again. I put the easy reader in the sensor, pulled it out and it read 99%. I waited about 10 - 15 seconds and did it again in the same sensor. It jumped down to 96%, repeated and then I got a 95%.

Why would it be getting different readings over multiple successive readings? Could the easy reader be bad?

My understanding is that all you have to do is put the reader in the sensor, wait a few seconds until it registers and pull it out and then that is your reading. It shouldn't take multiple inserts to read.

Any info is appreciated.

Thanks,

Jeremy]]>
I took readings approximately 1 day, 3 days and now a few weeks after installing the sensors. They've all came back at 99%. It is known to all involved that the slab is fairly wet.

The contractor had the vct contractor perform some relative humidity tests in the same area that my tests are in. He is getting readings in the mid 80's.

I went back to the site today and took readings again. I put the easy reader in the sensor, pulled it out and it read 99%. I waited about 10 - 15 seconds and did it again in the same sensor. It jumped down to 96%, repeated and then I got a 95%.

Why would it be getting different readings over multiple successive readings? Could the easy reader be bad?

My understanding is that all you have to do is put the reader in the sensor, wait a few seconds until it registers and pull it out and then that is your reading. It shouldn't take multiple inserts to read.

Any info is appreciated.

Thanks,

Jeremy]]> <![CDATA[Adhesive/Vapor Retarding Membranes. ]]> http://www.wagnermeters.com/concreteforum/showthread.php?tid=262 Sat, 31 Mar 2012 23:27:05 +0000 http://www.wagnermeters.com/concreteforum/showthread.php?tid=262
http://www.bostik-us.com/files/tdsfiles/Vapor-Lock.pdf

Quote:Quote Bostik "For substrates that have an MVER of greater than 15 lbs or an RH
greater than 85% or for substrates where a vapor retarder is not
used or is not functioning below slab, use Bostik Ultra-Set® Single-
Step™or Bostik MVP4/Bostik Adhesive System."

Hmmm, what-a-da-yas-think?]]>
http://www.bostik-us.com/files/tdsfiles/Vapor-Lock.pdf

Quote:Quote Bostik "For substrates that have an MVER of greater than 15 lbs or an RH
greater than 85% or for substrates where a vapor retarder is not
used or is not functioning below slab, use Bostik Ultra-Set® Single-
Step™or Bostik MVP4/Bostik Adhesive System."

Hmmm, what-a-da-yas-think?]]> <![CDATA[StarBucks]]> http://www.wagnermeters.com/concreteforum/showthread.php?tid=261 Thu, 29 Mar 2012 00:24:13 +0000 http://www.wagnermeters.com/concreteforum/showthread.php?tid=261 ]]> ]]> <![CDATA[ASTM E1907 ?!?]]> http://www.wagnermeters.com/concreteforum/showthread.php?tid=260 Tue, 27 Mar 2012 20:31:17 +0000 http://www.wagnermeters.com/concreteforum/showthread.php?tid=260
Can anyone give me some background on it?

I read it was withdrawn and replaced by F710. So.... what should I think?

http://www.astm.org/Standards/E1907.htm]]>
Can anyone give me some background on it?

I read it was withdrawn and replaced by F710. So.... what should I think?

http://www.astm.org/Standards/E1907.htm]]> <![CDATA[How thick is your floor? ]]> http://www.wagnermeters.com/concreteforum/showthread.php?tid=259 Tue, 27 Mar 2012 17:23:03 +0000 http://www.wagnermeters.com/concreteforum/showthread.php?tid=259
I was called in and tested a few locations using the same Rapid RH (is there anything else? Tongue ) and concurred with the flooring sub that the floor was too wet for the flooring they were installing.

The floor was put in anyway, using a latex sealer and 'special' glue. It is failing just a few months later.

I was called in again and asked to evaluate the slab, starting with RH. This is where things get more serious. We have a failure so now we have to ramp it up a bit. Even though I am being told the slab is 4" thick, I need to verify that it really is. Well guess what?

It isn't.

I drilled depth holes approximately 8" from my new test holes and measured the slab between 4" and up to 8" thick.

Now that there is a problem, I am rethinking my original testing. I did say the slab was too wet so I am kind of safe there, but if they go off my original readings and based their sealer on that, was I off? Either way, my readings were over 90% and even the Wagner can vary by 3% at that high of RH so we could have been at 94% to 97% easily.
I sure never said the slab was at or below 90%. And we were looking for 75% so if my probes were too shallow and reading 90%, going deeper would have been even wetter.

Perhaps there are grade beams in the ground that were not noted. Maybe there are grade beams down low, then vapor retarder was installed and the top 4" is separated from the thicker concrete. If that is the case my new readings could be erroneous because I have some at 3.2" deep!

It's too early to tell, but there will be a lot of questions asked in the near future. Slabs on grade are notoriously uniform in my experience, unless there was something buried or beefed up. No concrete installer wants to pay for extra slab thickness and no GC is going to let him pour less than he bid. Slabs just don't tend to vary more than half an inch on grade and a good sprinkling of readers will catch any discrepancy.

It could be that all the original probes were put in 4" concrete and I just happened to hit the thick parts now because I am installing along supporting walls to stay out of the way.

I'll let you know what comes out in the wash.]]>
I was called in and tested a few locations using the same Rapid RH (is there anything else? Tongue ) and concurred with the flooring sub that the floor was too wet for the flooring they were installing.

The floor was put in anyway, using a latex sealer and 'special' glue. It is failing just a few months later.

I was called in again and asked to evaluate the slab, starting with RH. This is where things get more serious. We have a failure so now we have to ramp it up a bit. Even though I am being told the slab is 4" thick, I need to verify that it really is. Well guess what?

It isn't.

I drilled depth holes approximately 8" from my new test holes and measured the slab between 4" and up to 8" thick.

Now that there is a problem, I am rethinking my original testing. I did say the slab was too wet so I am kind of safe there, but if they go off my original readings and based their sealer on that, was I off? Either way, my readings were over 90% and even the Wagner can vary by 3% at that high of RH so we could have been at 94% to 97% easily.
I sure never said the slab was at or below 90%. And we were looking for 75% so if my probes were too shallow and reading 90%, going deeper would have been even wetter.

Perhaps there are grade beams in the ground that were not noted. Maybe there are grade beams down low, then vapor retarder was installed and the top 4" is separated from the thicker concrete. If that is the case my new readings could be erroneous because I have some at 3.2" deep!

It's too early to tell, but there will be a lot of questions asked in the near future. Slabs on grade are notoriously uniform in my experience, unless there was something buried or beefed up. No concrete installer wants to pay for extra slab thickness and no GC is going to let him pour less than he bid. Slabs just don't tend to vary more than half an inch on grade and a good sprinkling of readers will catch any discrepancy.

It could be that all the original probes were put in 4" concrete and I just happened to hit the thick parts now because I am installing along supporting walls to stay out of the way.

I'll let you know what comes out in the wash.]]> <![CDATA[Ardex V1200]]> http://www.wagnermeters.com/concreteforum/showthread.php?tid=258 Tue, 27 Mar 2012 16:57:10 +0000 http://www.wagnermeters.com/concreteforum/showthread.php?tid=258
We poured 100 bags on a job where two slab elevations were off and I ended up putting the V1200 in 2 1/2" thick (two lifts) and I was pleased to find ZERO cracking and a perfect finish.

We pumped in about 600 bags on a retail floor with some low areas and some feathering to nothing and it flows nice, heals nice and finishes nice. Very consistent! No surprises when it's warm in a building or cool. We've mixed with differing water temps and it always flows nicely.

Pricing is pretty good too if you buy in quantity.]]>
We poured 100 bags on a job where two slab elevations were off and I ended up putting the V1200 in 2 1/2" thick (two lifts) and I was pleased to find ZERO cracking and a perfect finish.

We pumped in about 600 bags on a retail floor with some low areas and some feathering to nothing and it flows nice, heals nice and finishes nice. Very consistent! No surprises when it's warm in a building or cool. We've mixed with differing water temps and it always flows nicely.

Pricing is pretty good too if you buy in quantity.]]> <![CDATA[pH Balance for the Same Price as Relative Humidity]]> http://www.wagnermeters.com/concreteforum/showthread.php?tid=257 Mon, 26 Mar 2012 05:28:19 +0000 http://www.wagnermeters.com/concreteforum/showthread.php?tid=257
Here is a link.

Why is there a basketball and b-ball court featured?

Was this part of the MFMA talk Jason gave? I'm wondering because I do gym floors.]]>
Here is a link.

Why is there a basketball and b-ball court featured?

Was this part of the MFMA talk Jason gave? I'm wondering because I do gym floors.]]> <![CDATA[Wow, just wow. ]]> http://www.wagnermeters.com/concreteforum/showthread.php?tid=256 Sat, 24 Mar 2012 13:17:09 +0000 http://www.wagnermeters.com/concreteforum/showthread.php?tid=256
There were some earlier changes, but what will happen in the near future is going to really rock my world.... Our world. Sad

I can't say anything more right now.]]>
There were some earlier changes, but what will happen in the near future is going to really rock my world.... Our world. Sad

I can't say anything more right now.]]> <![CDATA[World of Concrete 2012]]> http://www.wagnermeters.com/concreteforum/showthread.php?tid=255 Fri, 23 Mar 2012 16:40:42 +0000 http://www.wagnermeters.com/concreteforum/showthread.php?tid=255
Are they supposed to be secret?]]>
Are they supposed to be secret?]]> <![CDATA[Bosch De-Tect 150]]> http://www.wagnermeters.com/concreteforum/showthread.php?tid=254 Thu, 15 Mar 2012 15:53:45 +0000 http://www.wagnermeters.com/concreteforum/showthread.php?tid=254 <![CDATA[99 % RH]]> http://www.wagnermeters.com/concreteforum/showthread.php?tid=253 Wed, 07 Mar 2012 21:53:07 +0000 http://www.wagnermeters.com/concreteforum/showthread.php?tid=253 did moisture test, calcium chloride at 3.22lbs, RH test 99%
Moisture mitigation not in the budget.... Any suggestions on how to get VCT installed without problems]]> did moisture test, calcium chloride at 3.22lbs, RH test 99%
Moisture mitigation not in the budget.... Any suggestions on how to get VCT installed without problems]]> <![CDATA[Light Weight Concrete on Pan Deck]]> http://www.wagnermeters.com/concreteforum/showthread.php?tid=251 Thu, 01 Mar 2012 19:05:50 +0000 http://www.wagnermeters.com/concreteforum/showthread.php?tid=251 <![CDATA[improper probe depth]]> http://www.wagnermeters.com/concreteforum/showthread.php?tid=249 Thu, 23 Feb 2012 20:00:40 +0000 http://www.wagnermeters.com/concreteforum/showthread.php?tid=249 My training consisted of verbal instruction from a co-worker who had performed tests initially, and is no longer with the company, to reading the directions that came with the early readers. "Drill your holes 1 3/4 - 2" deep", he said.
From what I have learned in the last two days of research, on my own time and of my own initiative, is that I have been doing the tests correctly in every step, except for this one.
Now my superiors at my company are blaming me for not doing the tests correctly. Even though I was never given adequate instruction, I feel my job is in jeopardy. I do tests when asked to (infrequently), and I'm an installer (35 years experience, 17yrs. w/ company) primarily. This lapse has cost us a lot of money, not to mention unreliable results. Since I am not certified, and our company, not wanting to be held legally responsible for giving a go ahead for installation after high readings, another testing company is being brought in to verify our results. More time and money spent!
I want to be proficient at testing, and feel I am close, thanks to the information I have gained here. I will plead my case to my superiors for more education/knowledge/certification and see what happens. You guys really are Concrete Gurus!
Now to my question: having drilled holes 2" deep in a slab that is 3" thick, poured over a corrugated pan appox. 1/8" thick (according to some field measurements taken), what would the correct depth of holes be for the probes? .6" or 1.2" 20% or 40%? Also, if drilling .6", won't the probes stick out 1" above the slab? Is this normal, and how do you prevent them from damage from lifts, bakers, etc.?
I need to know where I made my mistake,for my own piece of mind, so hopefully, this will not occur ever again.]]> My training consisted of verbal instruction from a co-worker who had performed tests initially, and is no longer with the company, to reading the directions that came with the early readers. "Drill your holes 1 3/4 - 2" deep", he said.
From what I have learned in the last two days of research, on my own time and of my own initiative, is that I have been doing the tests correctly in every step, except for this one.
Now my superiors at my company are blaming me for not doing the tests correctly. Even though I was never given adequate instruction, I feel my job is in jeopardy. I do tests when asked to (infrequently), and I'm an installer (35 years experience, 17yrs. w/ company) primarily. This lapse has cost us a lot of money, not to mention unreliable results. Since I am not certified, and our company, not wanting to be held legally responsible for giving a go ahead for installation after high readings, another testing company is being brought in to verify our results. More time and money spent!
I want to be proficient at testing, and feel I am close, thanks to the information I have gained here. I will plead my case to my superiors for more education/knowledge/certification and see what happens. You guys really are Concrete Gurus!
Now to my question: having drilled holes 2" deep in a slab that is 3" thick, poured over a corrugated pan appox. 1/8" thick (according to some field measurements taken), what would the correct depth of holes be for the probes? .6" or 1.2" 20% or 40%? Also, if drilling .6", won't the probes stick out 1" above the slab? Is this normal, and how do you prevent them from damage from lifts, bakers, etc.?
I need to know where I made my mistake,for my own piece of mind, so hopefully, this will not occur ever again.]]> <![CDATA[ICRI in Chicago]]> http://www.wagnermeters.com/concreteforum/showthread.php?tid=248 Mon, 20 Feb 2012 01:24:19 +0000 http://www.wagnermeters.com/concreteforum/showthread.php?tid=248
So, looks like my first ever trip to the USA will be a whistle-stop for the ICRI course in Chicago for the week in May.

Any tips for a weary traveller? Best hotels? Sights in Illinois? Things to avoid?

I don't know about spending a gazillion hours on a plane to be stuck in one place for a week. But I am kinda excited.

And of course, I get to be educated by the industry's finest in a technical field of vital industry developments. That's good too.]]>
So, looks like my first ever trip to the USA will be a whistle-stop for the ICRI course in Chicago for the week in May.

Any tips for a weary traveller? Best hotels? Sights in Illinois? Things to avoid?

I don't know about spending a gazillion hours on a plane to be stuck in one place for a week. But I am kinda excited.

And of course, I get to be educated by the industry's finest in a technical field of vital industry developments. That's good too.]]> <![CDATA[I talked but she didn't listen!! ]]> http://www.wagnermeters.com/concreteforum/showthread.php?tid=247 Wed, 25 Jan 2012 19:31:09 +0000 http://www.wagnermeters.com/concreteforum/showthread.php?tid=247
She called me and described the floor colors and textures and warranties, and how the installer had his own guys and never subbed work out....

I of course explained my concern that she has her slab properly tested for moisture before she has a wood floor installed.

She said they install floors all the time in houses like hers and they are beautiful and easy to clean and blah blah blah.

I said I'd ask for Wagner Rapid RH testing. The three probes will cost less than 1% of the total price of the install and you will know the health of your concrete slab.

She said, "Oh yeah, they said they test the concrete first", then went back to rambling about the decision between a natural bamboo or a laminate floating floor.

I told her if they use a CaCl test, the new ASTM requires grinding the slab, waiting 24 hours, installing the kit and then waiting 72 hours to weigh the test. Don't let them just slap a kit down, and really you should demand a Rapid RH test!

She said if she signs today, they can have the floor installed Monday. She just wasn't sure if the bamboo was worth the extra $2300.

It was obvious she wasn't hearing what I was saying. And in my mind, I had been bringing up the most important aspect of flooring on concrete. I believe the mental block is that if her floor doesn't pass the test I want her to do, she will either have to give up on getting a new floor, or it will cost her more money to install it.

I explained to her that if her floor were to fail down the road, she will probably face an installer that will tell her the concrete tested okay when he installed it, so something must have changed.

She said it must be fine because the carpet has been down for years and there's no trouble with that.

I told her that yes the carpet will allow the slab to dry, but what if they didn't put down a vapor retarder or what if there's a blotter layer or what if the retarder is full of holes? A Rapid RH has a good chance of picking up those clues.

She asked if I'm putting a laminate in my new addition, or staying with solid wood...

I wasn't getting through at all. I gave up. I asked her to call after the installer did his testing. I will keep you posted on what testing is done before this guy does the job and walks off with her money.]]>
She called me and described the floor colors and textures and warranties, and how the installer had his own guys and never subbed work out....

I of course explained my concern that she has her slab properly tested for moisture before she has a wood floor installed.

She said they install floors all the time in houses like hers and they are beautiful and easy to clean and blah blah blah.

I said I'd ask for Wagner Rapid RH testing. The three probes will cost less than 1% of the total price of the install and you will know the health of your concrete slab.

She said, "Oh yeah, they said they test the concrete first", then went back to rambling about the decision between a natural bamboo or a laminate floating floor.

I told her if they use a CaCl test, the new ASTM requires grinding the slab, waiting 24 hours, installing the kit and then waiting 72 hours to weigh the test. Don't let them just slap a kit down, and really you should demand a Rapid RH test!

She said if she signs today, they can have the floor installed Monday. She just wasn't sure if the bamboo was worth the extra $2300.

It was obvious she wasn't hearing what I was saying. And in my mind, I had been bringing up the most important aspect of flooring on concrete. I believe the mental block is that if her floor doesn't pass the test I want her to do, she will either have to give up on getting a new floor, or it will cost her more money to install it.

I explained to her that if her floor were to fail down the road, she will probably face an installer that will tell her the concrete tested okay when he installed it, so something must have changed.

She said it must be fine because the carpet has been down for years and there's no trouble with that.

I told her that yes the carpet will allow the slab to dry, but what if they didn't put down a vapor retarder or what if there's a blotter layer or what if the retarder is full of holes? A Rapid RH has a good chance of picking up those clues.

She asked if I'm putting a laminate in my new addition, or staying with solid wood...

I wasn't getting through at all. I gave up. I asked her to call after the installer did his testing. I will keep you posted on what testing is done before this guy does the job and walks off with her money.]]> <![CDATA[Help Please]]> http://www.wagnermeters.com/concreteforum/showthread.php?tid=246 Wed, 25 Jan 2012 00:19:33 +0000 http://www.wagnermeters.com/concreteforum/showthread.php?tid=246
My subcontractor has been taking moisture readings using his Rapid RH and getting readings consistently in the 95 - 99% range for three months without change. Because of these high readings he is demanding a $40,000 change order for moisture barrier. I watched the sub take his last set of readings and he stuck the probe in the hole and got a result in about 15 seconds. This seems contradictory to the ASTM acclimation of the probe statement.

So I had a testing company come out and take readings with their Delmhorst equipment. Readings came in at 67% and 77%. I reviewed the testing procedures with the tech and observed his procedures. I can find no fault with his work.

The sub of course does not agree and states the testing company did their tests wrong.

So now I have the sub conducting new tests in new locations and I am going to have the testing company observe.

Can anyone offer any advice as to what I should be looking for?

From what I have read most mistakes in testing procedures lead to high readings, is this correct?]]>
My subcontractor has been taking moisture readings using his Rapid RH and getting readings consistently in the 95 - 99% range for three months without change. Because of these high readings he is demanding a $40,000 change order for moisture barrier. I watched the sub take his last set of readings and he stuck the probe in the hole and got a result in about 15 seconds. This seems contradictory to the ASTM acclimation of the probe statement.

So I had a testing company come out and take readings with their Delmhorst equipment. Readings came in at 67% and 77%. I reviewed the testing procedures with the tech and observed his procedures. I can find no fault with his work.

The sub of course does not agree and states the testing company did their tests wrong.

So now I have the sub conducting new tests in new locations and I am going to have the testing company observe.

Can anyone offer any advice as to what I should be looking for?

From what I have read most mistakes in testing procedures lead to high readings, is this correct?]]> <![CDATA[Jason is a weenie]]> http://www.wagnermeters.com/concreteforum/showthread.php?tid=244 Wed, 18 Jan 2012 02:59:02 +0000 http://www.wagnermeters.com/concreteforum/showthread.php?tid=244
What he really did is make me jealous that he is in the land of beer, pretzels, pastries and delis while I am stuck here in the land of cold, fast food, and cheap swill..... Sad

I thought you were my friend Jason. Huh

Hoist a cold one for me and give a cheer! Prosit!]]>
What he really did is make me jealous that he is in the land of beer, pretzels, pastries and delis while I am stuck here in the land of cold, fast food, and cheap swill..... Sad

I thought you were my friend Jason. Huh

Hoist a cold one for me and give a cheer! Prosit!]]>