Some reading I've done says that MC should be less than 10% with no more than 4% difference between hardwood and subfloor. I've also read that MC should be no less than 12% with no more than 4% difference to subfloor.

Can MC be too low? I'm using two species of wood. The first species measured anywhere from 5.5% to 6.5%. The second measured 5.0% to 6.0%. The subfloor measured from 5.5% 6.8%.

Is there concern for low MC?

Thanks

I'd say your meter may be off and needs re-calibrating.

That is actually bout right, if you live in parts of AZ. or CO.

Are you making species corrections to obtain accurate readings? Also subfloors need to be corrected to. OSB, AdvanTech and pine plywood use three different corrections.

Discovering that standard OSB and AdvanTech do not use the same species correction factor was a surprise to me.

The MC tool was borrowed from a hardwood wholesaler, was good quality (Delmhorst J-4), and indicated OK when pressing the calibrate button. They use the tool in their own stock room. It also responded as expected when placing a finger across the probes.

I've only seen discussions about high MC as well as too much delta between hardwood and subfloor. The shop I borrowed it from said the hardwood should ideally read about 7%. I live in Minnesota and the RH is only high during a couple months in the summer. My air conditioning is on during high RH periods so I'm not anticipating any problems.

Delmhorst pin meters are calibrated to doug fir.... every reading must be species corrected for it be accurate. If you want you can post each reading along with what species of wood you are sticking... subfloor type too. Your readings might be close to accurate or they could off by quite a bit.

Thanks, but I neglected to mention that I did offset the measurements based on the table at the end of the users manual. One species was not in the table but a call to the manufacturer provided the offset to use.