You can not scan to give a rh reading. Rh= how much moisture is leaving a concrete floor. As my test prove, this can be low but will incrase if a barrier like vinyl is placed on top. As for wood, the RH could read low but once would is glued to it, well the wood will start to suck moisture out of it. So a floor reading 65% rh is technically o.k to install wood flooring on. Attach wood flooring to it and you now start sucking teh moisture out. So in other words a subfloor that might tell you 65% rh will when a wood floor is glued to it actually start to release moisture at maybe 80% etc. Hence Sid Bourne has been saying for years that a surface DPM should ALWAYS be applied to a concrete subfloor when bonding real wood to it. Really annoying as he is always correct. these tests back up his theroys every time. One would think that he has been here and done that many years ago. MC= (scan mode with a scale from 0 - 6.9 %) is a scale where teh moisture reader is working out what percentage BY WEIGHT is moisture in the concrete. NOT WHAT IS LEAVING the concrete (RH measures that bit) . However, think about it. A MC result has told you how much moister is there. That moisture will try and leave the concrete. At what speed we dont know with a MC test, that is what a RH test tells us. However, with a MC test we know its there. When we cover up concrete with vinyl / wood etc that hidden moisture is now going to build under vinyl or get sucked out by wood. Make sence?
Most meters out there can scan. MMS can scan for example. However the scale it scans in is promtimeters own scale. It is not any standard, it is a guide only Tramex in scan, scans to international standards. Its scan mode give a reading in MC which is telling you how much moisture by weight is in teh concrete. So in other words. If you have 1000KGS of concrete and it tells you the MC is 5% then that means that 50kg of the concretes weight is water. Thats a lot of water ! that will at some point try and leave the concrete.
and it helps when you haven't got the time to go back and check.. just tell the customer when they call.. oh it needs abit more time...
Yes mate, the problem is that the reading was so slow moving that with a 24 hr period passing it was sat at what you would think was a constant reading.
1. My mistake, I thought BS only covered the hood method. 2. Fair point. I don't like pooh fans. 3. Hear hear...Although our European cousins talk a lot of sh*te too, so lets be careful
