Bad, Bad Testing

[Rubensgt40]

I was gonna say!

I never noticed that scale on the old MC Meter. Well, that answers that question. It's not RH%! Back to where we started.

Remember JD way back when I first waddled into this forum, with my nappies and training wheels, we were all using MC Meters down under and some spec sheets still call for the ubiquitous old 5.5% maximum threshold of MC, up to which everything is great, slap down a floor.

Indeed some installers still tell me "it's okay, I tested the concrete it was under 5.5%.".

Now the new resilient standard and many spec sheets tell you to forget MC, but don't throw your meters away just yet- they're good for mapping out where you should do further RH testing.