Gary \ FloorGuy,
I have been on this board for several weeks now researching for my upcoming flooring project (Aus Cypress over crawlspace). The flooring has been in my house now for just over 4 weeks. The moisture reading on my 3/4" subfloor is holding at 14~15% (no change in 4 weeks) and the house is maintained at 68~70 F and the hummidity readings are consistent at 50% over the last 2 weeks since I purchased the meter from RadioShack.

Issue:
The flooring has not changed as well, the meter readings are still at 6~7%. Most of the flooring is still in the box with the ends open. I did remove a few pieces and put them around the room. These pieces are also at 6~7%.

As a sanity check and for a comparison, I checked a relatives home this weekend to see if the floor moisture readings were in the same range. This home was built in the 60s and hase a pine slat subfloor with 2 1/4" Oak flooring (original to the home). It is located in the same community as my home. Both the sub-floor and the Oak read around 14~15% like the subfloor in my home. This makes me feel more confident that this is a normal reading for this part of the region (SW GA).

Has anyone out there had an similar acclimation issue? The Aus Cypress does not appear to be taking on much moisture in 4 weeks. I want to start the installation over the Holiday break, but I am wary of the readings since the wood has a differential of 8% at the moment. Any suggestions are welcome.

Is there a method for bringing the flooring up to within range of the subfloor (10~12%)? Given the readings at the other home, I doubt that the subfloor is going to drop to the recommended 12~14%. The crawl space vapor barrier has been in place for over two years so I don't think there is much I can do to reduce it more.

Thanks.....
Addison2481

Are you making species corrections for your meter? That is the most logical culprit. The meter should have come with a corretion table. Are you using it?

The meter is from Extech (M0 200). It did not come with a correction table. This is the first thing I assumed as well. I sent an email to their technical (calibration) department shown on their website two weeks ago before my business trip. But as of yet, they have not replied. I am going to try to call them as well.

takes a long time for that wood to accept the increase in moisture content and even longer for sub-floors to lower moisture content.
It ain't the meter.

I'm not about to dump on Extech, but I have never heard of them. I doubt you are getting accurate readings. Yours is a pin meter. It measures electrical resistance. The ohms of resistance will fluctuate with temp and species. The fact that they make no mention of correcting for species leads me to assume it is a less than accurate piece of diagnostic equipment.

15 percent is not normal in Phenix City or anywhere else. An easy test would be to simply nail a board down directly to the subfloor. If you truly have a 7-9 percent imbalance, that board will take on water pretty quick.

To reiterate; the problem is your equipment, not your home. I live in Dawsonville Ga, and it is as humid here in the mountains as it is down your way.

How long are the pins on this moisture meter??

I want an accurate humidity reading of the installation area, and I want an accurate humidity reading deep into the crawl space.

I betting you have about 45-50% interior Rh and about 80% crawl space Rh

OK...HERE'S AN UPDATE.

I CONTACTED AN EXTECH TECHINCAL REP TODAY BY PHONE. (YOU CAN GO TO THEIR WEBSITE. THEY MAKE VARIOUS TYPES OF INSTUMENTATION AND HAVE DIFFERENT LEVELS OF PRECISION METERS.) I CHOSE A MID-RANGE METER (MO 200 ~ $80), NOT THEIR BEST OF THE BEST, BUT A GOOD AVERAGE METER. THEY DO OFFER A UNIT THAT HAS PRE-SET CALIBRATION FOR DIFFERENT TYPES OF WOOD. IT RUNS IN THE HIGH $$$$. THE TECH POINTED OUT THAT THERE WAS NOT A CORRECTION SHEET FOR THE MO 200. THAT'S WHEN HE MENTIONED THEIR 407777 UNIT THAT HAS THE CORRECTION CAPABILITY BUILT IN TO IT. MORE MONEY THAN A DIY WOULD INVEST.

FLOORGUY,
THE PINS IN THE METER ARE 3/8". I WAS THINKING THE SAME THOUGHT AS YOU MAYBE. TONIGHT I PUSHED THEM DEEPER INTO THE WOOD. I ALSO NOTICED THAT THE METER IS VERY SENSITIVE TO THE ELECTRIC FIELD IN MY HANDS. WHEN I REMOVE MY HAND, THE METER HOLDS STEADY. IF I APPROACH IT, THE READINGS JUMP UP AND DOWN. I PULLED THRU SEVERAL BOXES, SOME DEEPR IN THE STACK AS WELL. I AM NOW GETTING AROUND 10~12% WITH THE PINS MUCH DEEPER AND WITH MY HAND OFF THE UNIT. SOME ARE STILL IN THE 8~9%, BUT I CANNOT PUSH AS DEEP IN THOSE PIECES.

THE INTERIOR READINGS ARE 50~53% NOW AND WE HAVE ABOUT 72% OUTSIDE. WHEN I FIRST PURCHASED THE RADIOSHACK UNIT 2 WEEKS AGO, I PLACED THE REMOTE SENSOR IN THE CRAWL SPACE AND COMPARED IT TO THE OUTSIDE READINGS. THEY MATCHED WITHIN A FEW POINTS. SO, I WOULD SAY THE CRAWL SPACE IS AT 72% TONIGHT. THE RECENT WEATHER HERE IN SW GA HAS BEEN HIGHER HUMMIDITY (80 ~ 90%).

I AM GOING TO LOOK FOR A LARGE FAN WITH HIGH CFM CAPABILITY AND SEE IF FORCED VENTALATION IN THE CRAWL SPACE WILL HELP DROP THE SUBFLOOR TO AROUND 12%.

Is there plastic COMPLETELY covering the soil inside the crawl space? If not, there is where you need to start.

ok guys,
why not take the wood out of the boxes and rack them out for faster acclimation,, if thinking it is needed, coat the back of the boards before installation,,,, Chuck! you know this,, any man who has been to the wood guild like you, a skilled wood man, gee, don't make me travel down I 85!
hey , I am just playing, don't pay any attention to me,
chuck, will call soon
slt

Lee, first off, whats your take on this ""The moisture reading on my 3/4" subfloor is holding at 14~15%"" and do you think that needs to be corrected first, before we even discuss acclimation.

I too find it hard to believe that the subfloor readings are accurate. I say that because the existing 2 1/4 hardwood would have cupped and the poster did not mention any problems with the old flooring.

Did you have any problems before with the old flooring?

First of all, thanks for all the responses.

Yes, a plastic moisture barrier has been in place for about two years now. The home is about 10yrs old. The HVAC is in the crawl space which compounds the problem. This is why I am now considering a fan system to move the air (forced ventalation). I will just have to monitor it so that it is off during times of high humidity outside.

The other home I checked was built in the eraly 60s and the Oak flooring is not cupping. This is my mothers home that I grew up in. The crawl space has always been extremely dry and dusty.

In my home, there was carpet down before. This is the first hardwood install in this home.

I spoke with an installer located in a neighboring city to see if they had a professional grade wood meter to confirm my readings. He is on vacation out of town at the moment. He suggested trying to bring the 14~15% down. This is why I am going to try forced ventalation to see if it helps.

Some areas of Georgia, as in Florida, have high humidity whereby the sub-floors are high in Wood Moisture Content.
Don't know where this man lives, but maybe need to find out more about the location and building.
Is the HVAC draining under the house?

I live in Southwest GA about 50 miles North of Tallahassee, FL.

The HVAC drain is outside the foundation wall.

Most of my MC testing in SC, GA and parts of TN/NC will be between 12 to 16%,,,,
so,,,, remember the MC will be directly related to the area's RH/Temp,,,, then remember what happens in the cooler crawl space to the RH when it hits the cooler air,,,,so,,,, it will take longer to acclimate in these areas but here is the positive side of wood in those areas, they are very stable since there will be very little mc / temp change to make MC swings in the wood,,,, for example, when the wood in Charleston SC is correctly acclimated, it never cups or you get gaps,
slt