http://www.wagnermeters.com/concreteforum/ Thu, 29 Jul 2010 11:41:55 +0000 MyBB http://www.wagnermeters.com/concreteforum/showthread.php?tid=55 Sat, 24 Jul 2010 21:07:59 -0700 http://www.wagnermeters.com/concreteforum/showthread.php?tid=55
It seems that we found a crack that went all the way through a cast in place deck and the epoxy dripped right on a doctor as he was conducting an x-ray.

I've heard the doc is pretty P.O.'d.

Oops.... :O]]>
It seems that we found a crack that went all the way through a cast in place deck and the epoxy dripped right on a doctor as he was conducting an x-ray.

I've heard the doc is pretty P.O.'d.

Oops.... :O]]> http://www.wagnermeters.com/concreteforum/showthread.php?tid=54 Thu, 08 Jul 2010 22:41:43 -0700 http://www.wagnermeters.com/concreteforum/showthread.php?tid=54 http://www.wagnermeters.com/concreteforum/showthread.php?tid=53 Thu, 08 Jul 2010 22:40:36 -0700 http://www.wagnermeters.com/concreteforum/showthread.php?tid=53 http://www.wagnermeters.com/concreteforum/showthread.php?tid=52 Sun, 27 Jun 2010 08:15:16 -0700 http://www.wagnermeters.com/concreteforum/showthread.php?tid=52
Oftentimes these other persons bring in testing equipment ( I won't say manufacturers' names ) and harvest readings that are much lower than my readings recorded using the Wagner Rapid RH probes.

This is very confusing for the facility owner and the principle decision makers. I launch into defensive mode, explaining with charts and test data how slabs that are very young (maybe only two months old) and exposed to the elements just cannot be 50% - 60% RH as the opposing tests indicate. My next step is to pick away at the other probe's faults: Were the probes calibration checked within the last 30 days? Were the probes properly acclimated at each hole? Were the holes properly prepared?

In the end the Wagner probes are always proven to be correctly reading the RH levels in the slab, but weeks have been wasted and hopes of the owner pushing forward without mitigation expense are dashed. Stress levels are high, feelings are hurt, and there is no joy in proving the RH is way too high to put flooring down.

I always do my best to convince the other testing companies to adopt the Wagner system so we all don't have to go through this uncomfortable and time consuming process again.

My point here is to test your slabs and question the results. There is no way a fresh concrete slab is at 50% RH, so find out why the probe is reading incorrectly and try to remove that problem from your future testing. Time, conditions and readings will always follow a trend and make sense. If they don't you have to throw up a flag and find out why.]]>
Oftentimes these other persons bring in testing equipment ( I won't say manufacturers' names ) and harvest readings that are much lower than my readings recorded using the Wagner Rapid RH probes.

This is very confusing for the facility owner and the principle decision makers. I launch into defensive mode, explaining with charts and test data how slabs that are very young (maybe only two months old) and exposed to the elements just cannot be 50% - 60% RH as the opposing tests indicate. My next step is to pick away at the other probe's faults: Were the probes calibration checked within the last 30 days? Were the probes properly acclimated at each hole? Were the holes properly prepared?

In the end the Wagner probes are always proven to be correctly reading the RH levels in the slab, but weeks have been wasted and hopes of the owner pushing forward without mitigation expense are dashed. Stress levels are high, feelings are hurt, and there is no joy in proving the RH is way too high to put flooring down.

I always do my best to convince the other testing companies to adopt the Wagner system so we all don't have to go through this uncomfortable and time consuming process again.

My point here is to test your slabs and question the results. There is no way a fresh concrete slab is at 50% RH, so find out why the probe is reading incorrectly and try to remove that problem from your future testing. Time, conditions and readings will always follow a trend and make sense. If they don't you have to throw up a flag and find out why.]]> http://www.wagnermeters.com/concreteforum/showthread.php?tid=51 Sun, 13 Jun 2010 09:52:12 -0700 http://www.wagnermeters.com/concreteforum/showthread.php?tid=51
They are lucky if they do their testing BEFORE they install the new flooring, but sometimes these installers are shocked to receive failure complaints only a few weeks after installation.

Old flooring sometimes breathes better than what we install today, and the adhesives of the past are no longer allowed for modern installations. A slab that held a floor previously may not be suitable for new products. And those old 6 mil vapor retarders break down over time, so I advise testing on any slab where the pedigree is not known, or the slab is over 10 years old. Even then, I always put in a couple RH probes for peace of mind.

Better to catch that moisture before the installation and deal with it up front!]]>
They are lucky if they do their testing BEFORE they install the new flooring, but sometimes these installers are shocked to receive failure complaints only a few weeks after installation.

Old flooring sometimes breathes better than what we install today, and the adhesives of the past are no longer allowed for modern installations. A slab that held a floor previously may not be suitable for new products. And those old 6 mil vapor retarders break down over time, so I advise testing on any slab where the pedigree is not known, or the slab is over 10 years old. Even then, I always put in a couple RH probes for peace of mind.

Better to catch that moisture before the installation and deal with it up front!]]> http://www.wagnermeters.com/concreteforum/showthread.php?tid=50 Wed, 09 Jun 2010 16:25:12 -0700 http://www.wagnermeters.com/concreteforum/showthread.php?tid=50

Personally I have never heard or seen any reusable rh probes that does not utilize a sleeve of some kind or a stop gap rubber seal like on the old ones. He says and I quote " have not seen any data regarding the difference in RH readings made with and without sleeves. If any exists I would certainly welcome the opportunity to evaluate it. Of course the effect of a sleeve can be easily and cheaply achieved by using a metal foil tape formed into a cylindrical shape and placed into the drilled hole."

Don't want to name names but this guy does seminars and charges plenty. Knows lots of wood science though.

Is he correct or not?]]>

Personally I have never heard or seen any reusable rh probes that does not utilize a sleeve of some kind or a stop gap rubber seal like on the old ones. He says and I quote " have not seen any data regarding the difference in RH readings made with and without sleeves. If any exists I would certainly welcome the opportunity to evaluate it. Of course the effect of a sleeve can be easily and cheaply achieved by using a metal foil tape formed into a cylindrical shape and placed into the drilled hole."

Don't want to name names but this guy does seminars and charges plenty. Knows lots of wood science though.

Is he correct or not?]]> http://www.wagnermeters.com/concreteforum/showthread.php?tid=49 Sat, 29 May 2010 10:18:50 -0700 http://www.wagnermeters.com/concreteforum/showthread.php?tid=49 hi !

could anyone help me to find an instrument which i could measure the temperature at one point inside of concrete!!
]]> hi !

could anyone help me to find an instrument which i could measure the temperature at one point inside of concrete!!
]]> http://www.wagnermeters.com/concreteforum/showthread.php?tid=48 Sun, 09 May 2010 03:31:57 -0700 http://www.wagnermeters.com/concreteforum/showthread.php?tid=48 From sensors placed in the floor, obtaining ERH levels, or calculating specific humidity (SH) and comparing it to ambient or undertaking a Speedy Calcium CARBIDE test? I am often coming across situations where ERH readings are up in the 90%'s, yet carbide and SH readings indicate bone dry? Can anyone answer this? ( Before anyone says, i have a method for undertaking the carbide test that does not allow distortion by heat from the drilling or crushing)]]> From sensors placed in the floor, obtaining ERH levels, or calculating specific humidity (SH) and comparing it to ambient or undertaking a Speedy Calcium CARBIDE test? I am often coming across situations where ERH readings are up in the 90%'s, yet carbide and SH readings indicate bone dry? Can anyone answer this? ( Before anyone says, i have a method for undertaking the carbide test that does not allow distortion by heat from the drilling or crushing)]]> http://www.wagnermeters.com/concreteforum/showthread.php?tid=47 Tue, 27 Apr 2010 01:33:12 -0700 http://www.wagnermeters.com/concreteforum/showthread.php?tid=47 i want to measure the thermal conductivity and moisture inside of concrete(scc)!!
could anyone help me to find such standard methods;using simple instrument??
and plz help me to find thasts ASTM numbers for measuring thermal conductivity and moisture conductivity!!!]]> i want to measure the thermal conductivity and moisture inside of concrete(scc)!!
could anyone help me to find such standard methods;using simple instrument??
and plz help me to find thasts ASTM numbers for measuring thermal conductivity and moisture conductivity!!!]]> http://www.wagnermeters.com/concreteforum/showthread.php?tid=46 Wed, 17 Mar 2010 09:17:13 -0700 http://www.wagnermeters.com/concreteforum/showthread.php?tid=46
I am being aksed by a general contractor (infact by the product manufacturer) to use one RH measuring product over the other and I am not sure which one is more reliable. I fundamentally agree to using RH testing as a means to evaluate the concrete floors prior to installing flooring over it. However, when given a choice between using a removable RH probe (using a sleeve like IntelliRock Humidity Loggers or GE Protimeter) versus Insitu probe (like the one by Wagner), I am not sure if one is better than the other or, both provide similar results? Both product manufacuters claim that their probes are calibrated, but I believe the way these probes measure the RH is different (correct me if I am wrong).

We had a conflicting situation on a project where the removable probes gave lower RH readings (in lower 80% range) versus insitu probes (in lower 90% to upper 80% range) on a newly constructed slab-on-grade at similar temperatures. From what I understand, the Rapid RH probe measure the RH at 40% of slab depth while the other removable probes provide an average of the RH through the entire depth of the drilled hole. So I am inclined to say that since the surface is drier compared to the bottom of the hole, the average RH will be lower compared to the RH at the bottom of the hole. But the question is.....which reading should I use for making a decision on laying the flooring? Is the 75% RH requirement per F2170 valid for which test method???

Untill this project came across, I had been using the Rapid RH insitu probes, but I need enlightening from you experts on which kind of product is better and how to interpret the results?

Thanks]]>
I am being aksed by a general contractor (infact by the product manufacturer) to use one RH measuring product over the other and I am not sure which one is more reliable. I fundamentally agree to using RH testing as a means to evaluate the concrete floors prior to installing flooring over it. However, when given a choice between using a removable RH probe (using a sleeve like IntelliRock Humidity Loggers or GE Protimeter) versus Insitu probe (like the one by Wagner), I am not sure if one is better than the other or, both provide similar results? Both product manufacuters claim that their probes are calibrated, but I believe the way these probes measure the RH is different (correct me if I am wrong).

We had a conflicting situation on a project where the removable probes gave lower RH readings (in lower 80% range) versus insitu probes (in lower 90% to upper 80% range) on a newly constructed slab-on-grade at similar temperatures. From what I understand, the Rapid RH probe measure the RH at 40% of slab depth while the other removable probes provide an average of the RH through the entire depth of the drilled hole. So I am inclined to say that since the surface is drier compared to the bottom of the hole, the average RH will be lower compared to the RH at the bottom of the hole. But the question is.....which reading should I use for making a decision on laying the flooring? Is the 75% RH requirement per F2170 valid for which test method???

Untill this project came across, I had been using the Rapid RH insitu probes, but I need enlightening from you experts on which kind of product is better and how to interpret the results?

Thanks]]> http://www.wagnermeters.com/concreteforum/showthread.php?tid=45 Wed, 03 Feb 2010 12:41:26 -0800 http://www.wagnermeters.com/concreteforum/showthread.php?tid=45
A little tidbit I found in some lit:

302.2R-18 ACI COMMITTEE REPORT

"shown that the adhesive strength decreases with an increase
in the concrete’s MVER. When these tests were conducted,
however, there were no criteria for acceptable bond strength,
and scatter in the test results did not indicate a clear dividing line
between acceptable and nonacceptable adhesive bond strength.
A report on recent testing that attempted to correlate moisture
in the concrete with floor covering performance concluded
that: “The evidence presented suggests that there is no
relationship between the relative humidity of a concrete base
or screed and adhesion of resilient floor coverings” (The
Concrete Society 2004).
While moisture criteria are often used, the relationship
between these criteria and floor covering performance is not
well understood."]]>
A little tidbit I found in some lit:

302.2R-18 ACI COMMITTEE REPORT

"shown that the adhesive strength decreases with an increase
in the concrete’s MVER. When these tests were conducted,
however, there were no criteria for acceptable bond strength,
and scatter in the test results did not indicate a clear dividing line
between acceptable and nonacceptable adhesive bond strength.
A report on recent testing that attempted to correlate moisture
in the concrete with floor covering performance concluded
that: “The evidence presented suggests that there is no
relationship between the relative humidity of a concrete base
or screed and adhesion of resilient floor coverings” (The
Concrete Society 2004).
While moisture criteria are often used, the relationship
between these criteria and floor covering performance is not
well understood."]]> http://www.wagnermeters.com/concreteforum/showthread.php?tid=41 Thu, 21 Jan 2010 13:30:24 -0800 http://www.wagnermeters.com/concreteforum/showthread.php?tid=41 Thanks.]]> Thanks.]]> http://www.wagnermeters.com/concreteforum/showthread.php?tid=40 Thu, 14 Jan 2010 12:11:25 -0800 http://www.wagnermeters.com/concreteforum/showthread.php?tid=40
Thanks for the help.]]>
Thanks for the help.]]> http://www.wagnermeters.com/concreteforum/showthread.php?tid=39 Sun, 06 Dec 2009 14:00:15 -0800 http://www.wagnermeters.com/concreteforum/showthread.php?tid=39 It seems that there are still some flooring products that specify lbs/24 hours rather than RH%.

Thanks

CFI]]> It seems that there are still some flooring products that specify lbs/24 hours rather than RH%.

Thanks

CFI]]> http://www.wagnermeters.com/concreteforum/showthread.php?tid=38 Sun, 22 Nov 2009 10:36:53 -0800 http://www.wagnermeters.com/concreteforum/showthread.php?tid=38
I would like to be able to refer to a document that I could give my customers that tells them what is the criteria for meaningful moisture testing and what needs to be done to lower the RH in the slab as quickly as possible.

Is there an authority where I could get these guidelines?

Thanks for your help.]]>
I would like to be able to refer to a document that I could give my customers that tells them what is the criteria for meaningful moisture testing and what needs to be done to lower the RH in the slab as quickly as possible.

Is there an authority where I could get these guidelines?

Thanks for your help.]]> http://www.wagnermeters.com/concreteforum/showthread.php?tid=37 Sat, 21 Nov 2009 19:20:51 -0800 http://www.wagnermeters.com/concreteforum/showthread.php?tid=37 Currently I'm trying to assist a client with a problem as follows ...
New construction concrete mid-rise, occupancy started spring of this year. Client has been living in a 2 bed Condo for about 6 months and feels the place is making them sick. Unit has about 1300+ sqft. of exposed concrete on the walls and ceilings.
I took various moisture/RH readings.
Concrete surface 30-45%
1/8"-1/4" subsurface 50-75%
1" subsurface 80-99.9%
ambient RH 17-22%
At first I thought this might be an issue of emissions but based on the low ambient RH, I'm wondering if all the concrete isn't sucking the place dry.
Client states walls darken when it rains outside and portions of the floor blister up. Wood laminate floor over vapor barrier.
I've done other inspection work for this client and have made it clear that this isn't my field of expertise. I'm looking for information and ideas on what could be going on here so that I can point the client in the right direction.
I grew up in the trades on jobsites, so I'm pretty hearty and not the sensitive type. I started getting congested after an hour in the place.
Any thoughts or references for things to read are greatly appreciated.
Thanks Markus]]> Currently I'm trying to assist a client with a problem as follows ...
New construction concrete mid-rise, occupancy started spring of this year. Client has been living in a 2 bed Condo for about 6 months and feels the place is making them sick. Unit has about 1300+ sqft. of exposed concrete on the walls and ceilings.
I took various moisture/RH readings.
Concrete surface 30-45%
1/8"-1/4" subsurface 50-75%
1" subsurface 80-99.9%
ambient RH 17-22%
At first I thought this might be an issue of emissions but based on the low ambient RH, I'm wondering if all the concrete isn't sucking the place dry.
Client states walls darken when it rains outside and portions of the floor blister up. Wood laminate floor over vapor barrier.
I've done other inspection work for this client and have made it clear that this isn't my field of expertise. I'm looking for information and ideas on what could be going on here so that I can point the client in the right direction.
I grew up in the trades on jobsites, so I'm pretty hearty and not the sensitive type. I started getting congested after an hour in the place.
Any thoughts or references for things to read are greatly appreciated.
Thanks Markus]]> http://www.wagnermeters.com/concreteforum/showthread.php?tid=36 Sun, 08 Nov 2009 15:17:36 -0800 http://www.wagnermeters.com/concreteforum/showthread.php?tid=36 http://www.wagnermeters.com/concreteforum/showthread.php?tid=35 Mon, 21 Sep 2009 16:27:39 -0700 http://www.wagnermeters.com/concreteforum/showthread.php?tid=35 http://www.wagnermeters.com/concreteforum/showthread.php?tid=34 Mon, 21 Sep 2009 05:59:08 -0700 http://www.wagnermeters.com/concreteforum/showthread.php?tid=34 http://www.wagnermeters.com/concreteforum/showthread.php?tid=33 Mon, 07 Sep 2009 15:34:19 -0700 http://www.wagnermeters.com/concreteforum/showthread.php?tid=33 levels.concrete is poured six months rh is still reading at 90%]]> levels.concrete is poured six months rh is still reading at 90%]]>