I get these calls all the time because of some of my articles online. This one from an arid zone in California.
Customer buys stand T&G bamboo and has a young unsuspecting installer/GC install it with T&G adhesive.
So as usual it shrinks. No rh control, humidifier or check prior to and acclimated in the box. All wrong and now the kid has to deal with it.
So after years and multiple revisions for all these bamboo manufacturers installation guidelines due to failing floors in low ambient rh we see this; at first they wanted it acclimated in the box period, some still ask for minimum 40% rh (Cali Bamboo) which BTW is impossible to attain year round in arid zones:
From Morning Star
First, acclimate the new flooring in the areas to be installed
to the expected environment that the floor will service while in the boxes. If products are packaged in plastic, remove the plastic
wrapping from the outside of the boxes and open the ends of the boxes. If plastic is wrapped around the flooring inside of the boxes,
open the box ends only, cut away plastic to speed up the acclimation process increasing air-flow.
This is absolutely wrong! Opening the ends dries the ends of the planks more than the center causing gaps during installation. If you walk into a prospective job and see that WALK AWAY!
Now from Cali. They say totally unwrap and sticker stack cross wise which is great! I do that.
But here's another problem:
Use a reliable moisture meter that is acceptable for bamboo flooring. Strand-woven bamboo moisture readings must be converted to achieve accurate results. Contact the meter manufacture to verify substitute settings for bamboo. Meters that have adjustable species settings and conversion tables for strand-woven bamboo (such as Delmhorst; see table; right*) are most accurate. The flooring moisture content should vary less than 3% from the subfloor moisture content.
No moisture meter can read strand correctly due to the adhesives they use to bond the product together. The only method to determine this is the oven dry test. You may get close for instance I have quite a few strand planks in my office where the rh hovers around 30% all the time. I check these and then use my meter that has set number for strand and other bamboo. Then check against the new shipment.
And another issue;
Care should be taken to control fluctuating levels of moisture indoors, and to maintain humidity levels within the recommended 40-60% relative humidity range.
Still you can be off 3 to 5% easily. And these are the people who want 40% (morning star want 30% min) minimum rh all year round. Try that in an arid zone. Ain't probably going to happen unless it's been raining outside. And you want to be within 3% of the subfloor right? So how do you know?
Answer, YOU DON'T!! Truthfully bamboo should not be sold in arid zones,
Now go buy some domestic hardwood and sleep better.