We purchased strand bamboo nail down flooring, and it has been acclimating for about four weeks now.

Week 1-2 – We opened the ends of the boxes, as instructed, and staggered the pile of boxes so air could flow. The installers came and found the humidity around 30%. We were told that it was incorrect to only open the ends of the boxes since this particular type of wood has a lot of plastic inside the box.

Week 2-3 – Wood continues to acclimate, this time without any packaging, staggered to maximize air flow. The installers measured the humidity at 15% and said it was too high. They pulled back an area of the carpet, and the subfloor measured at 4%.

Week 3-4 – We have been running a dehumidifier 24/7 for the past week, and the wood still measures at 15%. We live in Virginia, it has not been especially humid this month, and we always keep doors and windows closed with the air conditioning on.

I am concerned that the humidity will never lower past 15% and the installation will be postponed indefinitely. I’m also worried that if we manage to force the humidity down to 10% (where it supposedly needs to be), the wood will expand the second it’s installed, causing major issues. The fact that our subfloor is at 4% makes me feel a little better, but not really, since they’re different woods. Another possible factor - the installers are not using the type of moisture meter that can be calibrated per wood species, so I thought that might be giving a weird reading. Also my husband is nuts and likes the AC at 66-68. Could this somehow be causing a damp environment?

Can anyone shed some light on this situation? If we need to let the wood acclimate more, I am fine with that, but I would like a second/third opinion. Is it reasonable to expect strand bamboo to be at 10% max before installation? Will we have problems with expansion once the wood is installed and we turn off the dehumidifier?

Thank you!

Do you have a basement?

what type of subfloors do you have?

my guess is both those readings are wrong..

I have a plywood subfloor, no basement - we're the top unit of a 3-story wood frame building.

After the 2nd visit by the installers, my husband and I rented the same type of moisture meter they were using, and both their meter and our meter are giving the same readings. If you think both readings are incorrect, what should we do to get an accurate measurement?

I believe the subfloor reading is way too low considering you live in a humid environment.

in NJ the AVG subfloor reading is usually around 10%..I cant imagine much difference for Va and I would expect probably slightly higher.

no one Issues climate control all year around and normal humidity levels are always present.

the meter must calibrate to read plywood as mine does.

many if not most meters unless spending a fortune and even then, don't have Bamboo calibrations because Bamboo is actually a grass..not wood.

if you don't have these specific calibrations in your meter, the readings you are getting are off..way off.

a meter with these capables start at the 350 range and up..the more you spend them more its capabilities..i have yet to see a meter that has a bamboo calibration.
not saying they don't exist..just haven't seen it.

further,

if you were getting reading 15% higher and have acclimated to this point..there is something significantly wrong which doesn't surprise me.

the stuff comes from China and there are known product failures and issues regarding bamboo flooring from there.

Hopefully you bought a quality trusted name brand.

that high a reading clearly demonstrates wet wood..it wasn't kiln dried properly.
but get an accurate reading before we assume anything.

the store you bought it from should be equipped to do this for you.

I find it odd that your installer wants the rh down to 10% when most bamboo manufacturers want it 30 to 50% rh. Virginia is like Appalachia is it not? With lots of trees???

Besides that I can't believe the subfloor is 4%. Most meters do not read that low. And no meter can correctly read a strand bamboo. Even the manufacturers in China do not use meters in the manufacturing process.

What kind of meter is he using?

I can tell you two things about bamboo I have learned. It shrinks and swell alot, just like regular hardwood if not more for all bamboo.

Four weeks to acclimate bamboo? Yup, could be more than that but I think his meter is screwy. When did he last have it calibrated or is it self calibrating?

They are using a Ryobi pinless meter: http://www.homedepot.com/p/Ryobi-Pinles ... kQybD8YF8E. They also had a pin meter with them which they used to confirm the readings, but I didn't catch the brand.

I know their Ryobi meter is functioning properly because we went out and rented the same one just so we could keep a closer eye on the situation. Our new one confirms their readings. This type of meter doesn't allow calibration for the wood species however. For the record, our subfloor read at 4% before we started using the dehumidifier.

Perhaps also of note, all off-gassing of the wood seems to be finished, which might suggest that it has acclimated all that its going to? However that doesn't mean the moisture levels are ok. It could still be a bad batch as someone else suggested.

On another thread I posted, someone suggested that we shouldn't wait for correct readings because of the resin in strand bamboo.

If we should just be patient, I'm fine with that. We've already planned on having 5/8" gaps everywhere to allow for a lot of movement. I'm having a hard time educating myself on what I should expect. The installers offered to send out a regional manager, and I think I'll take them up on that, but I want to gather as much information as I can from other sources (all of you).

Thanks for the input.

From that last bit if info IM convinced those readings are all wrong.


those Home depot meters are junk..Ryobi makes nothing but cheap tools and meters, but not to say they don't perform their basic tasks.

those meters are designed for framing lumber only..doug fir.

I absolutely agree,

I am confused you say humidity readings. Yet you say moisture meter! Do you mean relative humidity readings or moisture content?
And yes the Lignomat Versa Tec meter has strand bamboo settings at 20 for strand bamboo at 22 utilizing the meter in scan mode. Pin mode cannot be read due to the fact it is not solid but strands that comprise this type of grass. NWFA states is a wooden subfloor exceeds 12% moisture content to not proceed without finding out why. To accurately determine why testing testing testing will only determine why. But follow the mfg recommendations for bamboo are 35% to 55% relative humidity with temperature 60 to 80 degrees when not following the mfg's requirements the installer and homeowner are at risk not the mfg.
Most concerns I inspect happen because the installer or homeowner has not done so. 99% of the time it is not faulty wood.

I suppose I mean to say "moisture content" because I'm talking about the reading out of the moisture meter.

I install a lot of bamboo.
I use the Lignomat versa tec.( among many others)
Your installer really needs a better meter than he is using, also make sure (with a better meter) he is using a pin meter to test the subfloor scanners aren't as accurate.
Also is he taking multiple readings and averaging them out?
He should be taking tests equal to 3 to 4% of the flooring. So in other words 3 to 4 tests for every 100 square feet.
Bamboo does take longer to acclimate I have had them go 3 to 4 weeks quite often. With that said that Ryobi meter will give him much higher readings.
I would be leery of a guy using a $50 dollar meter to install thousands of dollars of my flooring.
I carry thousands of dollars worth of testing equipment. Pays to get it right the first time.

Well I just scheduled a meeting with the regional manager. He said he carries the Lignomat. He is going to do a complete assessment of environment, subfloor, and wood. Hopefully he will have a final answer for us. I'll keep my fingers crossed that we can proceed with the installation, and nothing is wrong with the wood!

Because of all the resins in strand woven, a pin type moisture meter is going to read on the high side as there is little resistance between the pin probes.

On a side note, because of the density and hardness of strand woven, I find nailing it down a very slow process. It all has to be drilled and hand nailed. Nailers will crack tongues and staplers will just fold the staples.

I have never tried using a pin meter on the flooring itself. The lignomat Versa tec has a scan mode for strand bamboo.

I wouldn't be concerned with the tongues cracking I install a lot of bamboo and don't have a problem with the tongues breaking. I use a primatech 18 gauge nailer, or the powernailer 18 gauge. Both work well for me. And I can install just about as fast as red oak.
I do have to drill and hand nail the starter rows however. I haven't been able to use my palm nailer to drive cleats in the bamboo they just tend to bend.