Atelier is right on the money as far as moisture testing is concerned and it is best to slab test on or right after high humidity and rainy days to get the worst-case-scenario test returns. The flooring system integrity will only be as good as it is in its worst day in the enviroment its installed in. After you get test results and compare them to the manufacturers product tolerances, then you can decide on the right product for that application or other remedies to bring it to withing manufacturer tolerances. The key here is prevention. Guessing isnt knowing, and any preventative measures used by guessing might be overkill OR might not be enough for the product. You just dont know without testing and in some cases an area will never be good enough for some products without rectifying the underlying construction causing the problem. Yes, some adhesives and substrate treatments will add a water vapor barrier and stop or stem hydrostatic pressure in the substrate but they all have cap limits. Owens Wood Flooring has a comptehensive information section of their site on Owens Plankfloor Gluedown Installation Owens states the following: "MAKE CERTAIN BUILDING INTERIOR AND SUBFLOOR ARE DRY Interior walls should be dry enough to be painted and a room temperature as required by adhesive manufacturer with a relative humidity of 30-50% should be provided before any installation begins. To determine if a concrete slab is suitable for hardwood flooring, please follow the NWFA guidelines to perform a Calcium Chloride test. If excessive moisture is present, do not lay flooring. Check floor in several locations. Concrete sub floors must be clean, flat and sound and of sufficient compression strength (3000lbs PSI) being sure that the surface is not slick. Sections not flat such as waviness, trowel marks, etc. are to be eliminated by grinding or the use of an acceptable leveling compound. Especially along the walls, the sub floor flatness must be checked and, if necessary, improved. Flat to 1/8" in an 8 radius. In addition to concrete sub floors, these products can be installed over dry, flat wood sub floors, such as plywood. If plywood is used as an overlay over an existing sub floor, the thickness of the overlay material much be such as to yield a total ¾" sub floor thickness. New wood type sub floors should also be checked for moisture using a moisture meter. In general, wood or plywood sub floors should not exceed 12% moisture content or 4% moisture content difference between wood flooring and sub floor." The NWFA is a resource you can only get information from if you are a paying member, so you might want to search around for the same information on calcium chloride tests from a independent source if you or your installer isnt a member. It should be noted that there are different types of moisture testing. 1. Relative Humidity of the Installation Area. 2. Moisture in the substrate itself hydrostatic Pressure. 3. Moisture testing the wood looring itself before the install to ensure its equalized to the within-tolerance installation area humidity. Here is some more information you may find useful: moisture testing hardwood flooring moisture testing for relative humidity in a room hydrostatic pressure in concrete ASTM F2170 ASTM F1869 your installer should be well educated in all of the above. ask them plenty of questions and get a good comfort level in their abilities. ask for and check out their references too.

Well, its been almost 6 months since you posted about your Bamboo - how did it go and how is it holding up??? We installed 1000 feet of this exact product in Nov 2012 - we are currently in the process of pulling it all up,, YUCH... moisture issue???? not really sure what happened,,, installer is being real good and standing behind it all - the house is 1/2 up and the rest is coming out tomorrow.. going with eng Hickory in its place - also laying down a very expense moisture barrier (painted on) Only used Glue that was suppose to have a moisture barrier in it??? floor was 14 years old in Central CA - maybe 10" of rain a year and NO problems in the past... anyway,, moisture test is in progress at this moment - Wish you luck with your Bamboo - wife liked it but it does NOT like any moisture and does NOT like spoons dropped on it,, LOL - still a very pretty floor,,, oh well, live moves on

Recipe for disaster. Concrete is porous, and thus absorbs moisture. When wood absorbs moisture, it swells. If it absorbs enough in the lower layer, with the top layer absorbing it slower, then you get cupping. Grooving will not prevent cupping. If you don't fix that constant transmission of moisture to the wood, then you get rotting. Wide plank already moves around a great deal, even when installed above grade on a subfloor. It will expand and contract with the seasons. That's normal. The wider the plank, the more movement you get. You need to maintain constant humidity in order to minimize the normal movement in wood. If you get hot and humid weather in the summer with no AC and don't use a humidifier in the dry winter air, then your wood floors, furniture, and cabinets will swell and shrink considerably over the seasons. That is NOT considered a defect. And this is why engineered flooring was created. It's basically plywood, with thinner layers of cross grained material. That means that each layer has minimal expansion and contraction, and because of the cross layers, it's much more stable. Combine that with a polyurethane glue designed to keep moisture transmission to a minimum, and that's the only consistent tried and true way to successfully have wood floors with slab flooring. It's the only way wood flooring is done here in the South, where humidity and concrete slabs are everywhere. It works, and there is no need to reinvent a square tire and call it a wheel.

AND.....the hits keep coming............ I have not seen any further activity in the house. I keep checking...but nothing. Holding my breath but hopeful. HOWEVER...today I decided to clean out my shed. It is an all wood 8x12 structure that I built myself in the corner of my backyard. It is built upon four 6x6 posts (embedded in concrete) and is four (to six) inches above the ground (suspended). I had a large hardwood tabletop and a big piece of butcher block countertop stored in there. As I was removing items I noticed a large blemish on the tabletop. I thought I might have scarred it with a bicycle that I'd had hanging next to it. Nope....termites. I pulled the tabletop (and butcher block) away from the wall and they were prettly well chewed up. I soaked them with bug killer (because I didn't want to unleash live insects into the wild) and hauled them to the curb. Then I noticed that tremites had chewed up the plywood inner wall of the shed. Mud tubes (might as well be..mud WALLS) were erected in the corner of the shed. One single mud tube went all the way to the ceiling. It had all been hidden by that giant tabletop. There was damage in one other area as well....and I could HEAR the termites munching away. The damage is pretty harsh but IS salvageable (and does not appear to be structural). I doused all the affected areas with Termiticide. The termites also munched on other pieces of scrap project wood I'd been storing in there. I trenched around the back and side of the shed and (in the back) found a LIVE cluster of termites and mud tubes centered around some decorative stones I'd placed around the base of the shed. This area is CONSTANTLY moist (due to rain and shade). I soaked the trench in termiticide (including the backfill) and will complete the treatment for the front and other side tomorrow. I am exhausted. If anyone else has gone through this...I feel your pain. The destruction of these little buggers is unreal. I am confident I can patch my shed up...but man....what a frustrating pest to deal with. Cheers.