RH Testing Thick Slabs - Printable Version
+- Concrete Moisture Measurement Forums (http://www.wagnermeters.com/concreteforum)
+-- Forum: Concrete (/forumdisplay.php?fid=1)
+--- Forum: Moisture Measurement in Concrete (/forumdisplay.php?fid=2)
+--- Thread: RH Testing Thick Slabs (/showthread.php?tid=336)
RH Testing Thick Slabs - CCR - 09-24-2012 06:21 PM
Anyone have suggestions for testing an 18" thick slab using the Wagner Reader?
With a 40% depth of 7.2", I'm afraid the reader will be diffucult if not impossible to remove. Slab was installed over Sega vapor barrier, but it will probably never dry in my lifetime, or my son's, or grandson's.
I wonder if I even need to set the sensors that deep. Wonder if the length of the reader less 1/4" to grab onto would suffice?
RE: RH Testing Thick Slabs - eaadams - 09-25-2012 09:25 AM
I have no idea but this begs the question what sort of building has a 18" slab and needs resilient flooring?
for my own edification please
RE: RH Testing Thick Slabs - CCR - 09-25-2012 10:03 AM
It's a testing lab clean room at a university where there will be heavy equipment moved over the surface causing a significant amount of vibration. Because of this, it had to follow very specific engineering specs for thickness, placement over a thick sand bed, vapor barrier , and isolation from adjoining slabs
RE: RH Testing Thick Slabs - eaadams - 09-25-2012 10:06 AM
I am not joking about this. Within 10 minutes of me doing the last post I got a call on a 14" slab. An old warehouse that had semi trucks drive in, load up and move on. So funny. JK - call wagner. Our tester says he got instructions from wagner on this 14" slab he is testing today.
RE: RH Testing Thick Slabs - CCR - 09-25-2012 10:13 AM
Thanks. I'll call now!
RE: RH Testing Thick Slabs - Rubensgt40 - 10-09-2012 07:07 PM
Any outcome on this?
We're starting to see 600mm deep sections of slab where raft-type designs are needed for extra stability in dodgy soil. I doubt you could get a Wagner to 240mm.
Are Wagner considering any accessories which might help?
RE: RH Testing Thick Slabs - CCR - 10-10-2012 02:10 PM
Since retrieving the Wagner reader in concrete deeper than the length of the reader is tricky, I set my sensors for the 18" slab at 5". My readings after 72 hours were all in the mid 90s. So you can pretty much figure the 40% depth of 7.2" would have been in the mid to upper 90s. ph tests confirmed the concrete was not ready for installation as those were all at 11 - 12.
Even without the thickness, the concrete was power troweled so much it was almost black. No way this slab is ever going to dry.
I will be following up with the contrator in a few days as a courtesy, as I did recommend the installation of a properly installed moisture mitigation system.
RE: RH Testing Thick Slabs - Ernesto - 10-10-2012 04:24 PM
If the top of the reader had a locking lugs cut into it to allow a tool to lock in so you could set the reader, then opposite to unlock I think you could go pretty deep.
RE: RH Testing Thick Slabs - CCR - 10-10-2012 04:58 PM
Good idea. But if the hole isn't perfectly straight, there could be enough resistance where insertion and removal could be a little tricky.
RE: RH Testing Thick Slabs - Ernesto - 10-10-2012 07:24 PM
(10-10-2012 04:58 PM)CCR Wrote: Good idea. But if the hole isn't perfectly straight, there could be enough resistance where insertion and removal could be a little tricky.
Yup, but you will be able to figure that out when you try and insert the sensor. Pull out and re-drill.
Of course this will mean a new model sensor insertion tool and reader with tool, The Rapid RH 5.0 EXTRA-EXTREME.
Don't thank me, just send me some new kits. I am but a poor flooring installer with needs.