About 6 months ago, my wife and I had new flooring installed in our house. Long story short, the man we hired to do the install was the wrong person for the job and we've learned our lesson about where we should and should not try to save a buck or two.

While the upstairs area is still fine (for now) the area downstairs started to buckle in one area, and almost the entire rest of the flooring ended up detaching and "floating" above the sub-floor (concrete). We removed a section of the wood flooring and discovered there was a significant amount of moisture underneath the wood.

We ended up ripping out all the flooring downstairs (more like "lifting" since there was almost no adhesion left to deal with) and we are having an experienced contractor install the replacement flooring in a couple days.

This time we will do a proper moisture test, and he plans on diamond grinding the concrete to ensure the floor is clear of any glue and primer that was left behind from the last job and ensure a solid bond with the glue. Yes...primer...I'm still pretty angry about that and not ready to talk about it in a calm manner.

The plan is to not lay the wood so close to the edges of the wall, to use a better glue (Bostik instead of Sika), and to install a vinyl barrier by putting a layer of glue on the concrete, lay down the moisture barrier, then lay down a layer of glue on TOP of the vinyl moisture barrier, and finally lay out the wooden floor on top of that.

This seems like a great way to ensure we have a solid moisture barrier in place and the contractor believes this is the only safe way to install a solid bamboo flooring over concrete when doing a glue-down installation since expansion can also be an issue.

My only concern with this method, which I think just stems from my lack of experience with this kind of work, is regarding the durability of including a vinyl barrier in this sandwich type installation. If I take two pieces of tape and stick them together (sticky side together), there is a strong bond. If I take two pieces of tape and then put a piece of thin shopping bag plastic between the two pieces of tape, then the plastic bag becomes the weakest link and makes it possible for me to tear one piece of tape away from the other.

I guess my question is, doesn't the vinyl barrier end up weakening the bond between the wooden flooring and the concrete slab? Also, if expansion is an issue with this type of bamboo, would expansion tear the barrier? I suppose perforating the vinyl barrier would allow the two layers of glue to have a stronger bond, but that kind of defeats the purpose of a barrier.

I'm confident in our new installer as he has plenty of experience, we've seen his past work, and he comes to us with good references. I'm just trying to educate myself a little bit about this and get some clarification without sounding like an idiot in front of the guy. Thanks for your help and patience!

Vinyl moisture barriers were common pre 2000 or so until spread type products became available. It's still used now and then but I would recommend to the T what the adhesive manufacturer recommends in this situation. Bostiks is a very strong adhesive which makes it mandatory (that's what I learned) it is also used to glue down the vinyl. Perhaps the new installer knows that already.

What Ken said, plus some adhesive manufacturers do not want their adhesive on vinyl or under it. Because there are so many these days you need to read the guidelines very carefully online and or the bucket itself. Usually the online version is more detailed. If still in doubt call the manufacturers number and ask for the tecnical dept.

Just guessing but since the vinyl blew off the floor the installer may have not used the proper adhesive to bond it to the concrete (your supposed to use the adhesive used for the wood on top) and may have just used a water based vinyl adhesive. In which case the wood moves more than the vinyl adhesive's ability to hold it to the floor especially in high MVE situations.

Do not poke holes in the vinyl if thats the method you choose, thats like shooting holes in plastic when putting down plywood as an underlayment over concrete.

Bostick has a number of good adhesive/vapor retarders out there. The best is Ultra-Set SingleStep and Ultra-Step SingleStep2

Scroll down to the specific one your looking for:

http://www.bostik-us.com/markets/flooring/hardwood

Edit: I just checked the TDS and here's what it says about bamboo and vinyl:

Thanks for the responses. The damaged flooring that we had to remove never had a moisture barrier installed. In an attempt to "seal" any moisture that may come through the concrete, the previous installer used a concrete primer (http://goo.gl/LCfus8) before laying down the Sika Glue and Wood. I didn't realize this was what was used until I was reviewing the receipts.The Sika glue stuck fine to the bottom side of the wood pieces, but none of it stuck to the concrete itself -- it just became this sticky pasty mess which I guess could be expected when you use the completely wrong materials.

So...a vinyl layer may not even be needed if the correct Bostik adhesive is purchased? We're obviously concerned about the moisture, but our installer seems equally concerned with gluing down any solid bamboo wood flooring to concrete as the flooring may expand/contract enough to cause buckling if we don't do the glue|vinyl|glue|wood sandwich. Is the glue itself supposed to take expansion into account? We've had the wood in the house with the ends of the boxes open for a couple days, so hopefully it's acclimated properly (something our last installer didn't do and said was not needed). Thanks again.

Big mistake not using a compatible sealer. As the instructions say, check for bond breakers prior to installation ie; paint, sealers and such. The only sealer you would want to use is the manufacturer's sealer if they have one. If in question do a bond test with some wood for a few days and see or call the tech dept.
Since I know nothing about this sealer, the installer better grind that slab really good, then a water droplet test to see if water will bead or penetrate. Otherwise the vinyl will no bond and you will have the same mess again. BUT!!! You don't need a sheet of vinyl as the adhesive is very elastic. Read the TDS on the link I gave you. READ READ READ

Before buying the adhesive I would recommend testing first. Some sealers penetrate the slab down to an inch so now you can't glue anything to it. You would need to lay down plywood which is another thread in itself.