Yes, it does look like an easy method to install flooring. I'm surprised to see maybe even ceramic. Not too sure about that one. It runs $2/sf. In this case it would save quite a bit of labor just on floor prep. There's adhesive on the slab which would otherwise need to be removed. It also provides a moisture barrier so he said solid wood could be used. I believe he even said 3/4 inch. Looking at the installation instructions, it looks to lay loose on the slab. I wonder what it's like to walk on one of these floors. If it feels like a regular wood floor. Another concern I have is how easy it is to replace a board. Or if a board goes crooked while trying to install it and you're already into the adhesive stage if you're stuck with a gap. Particularly worrisome when someone else is doing the install and maybe not as picky as you'd be yourself. The site says it has a worldwide patent but the salesman said that type of product has been used in Europe for over 20 years successfully. It's only new to the US. I'm looking into floating floors due to the adhesive on the slab but don't want a fake hollow sounding floor. The flooring stores I've been to don't seem to have sample floatings installed for people to check them out.

http://ths.gardenweb.com/discussions/2256276/how-long-should-foundation-concrete-cure?n=48 long discussion but heres a quote: macv Concrete does not actually harden by "curing" nor is there any point in time when concrete would be considered "cured." Concrete naturally hardens over time by "hydration", the chemical reaction between portland cement and water in the concrete mix. "Curing" describes a procedure that an installer may choose to use to insure more complete hydration of the portland cement (and therefore greater concrete strength) by controlling moisture loss during the critical early part of the hydration process (ie 3 to 7 days). In the case of a residential footing curing might consist of simply covering the concrete for 3 days. In any case the curing procedure would not normally continue beyond 5 or 7 days depending on the temperature of the air. 28 days has nothing to do with the maximum strength of concrete; it's just an arbitrary time chosen because the strength gained after that time period is normally not important from a design point of view and there has to be a standard measuring point in order to allow enforceable specifications and uniform strength testing. As long as moisture and a favorable temperature are present for hydration of the cement, the strength of new concrete continues to increase long after the early curing phase and the 28 day mark. Since the actual strength of the concrete in a residential footing is not particularly critical, testing is not required so the 28 day mark has no practical relevance in the field. In fact, if the concrete hasn't reached the minimum strength required by code in 7 days, it's unlikely to get there. The IRC requires a concrete footing to have a minimum compression strength of 2,500 psi which is a low value and easy to achieve (most specifications would be higher). If a concrete footing is reasonably protected for 3 days, it should have reached 70% of the minimum required strength and it should reach 100% by the 5th day. A lot of what they talk about is if the concrete is cured enough to continue construction on it. The general consensus in that thread is that it takes 2-3 days before continuing construction but I personally would wait at least a couple weeks if not a month in your application so extra moisture may release before the floor is laid. My biggest concern is with the moisture of the new slab affecting your floor. Any moisture that gets in engineered flooring will ruin them and cause expansion/buckling

I'm not a fan of putting down plywood over concrete just so you can have a nail-in-place hardwood. Soooo many ways this can (and will) go wrong. Personally, if you MUST have a wooden subfloor over concrete, please use a sleeper subfloor system built properly with the proper vapour barrier used. Or in the worst case scenario, something like DriCore (I'm not a big fan, but it will work when done PROPERLY....ahem, I'll say it again, "when done PROPERLY"). You still have to patch the concrete. After that, you can use a vapour barrier (see how you can't get away from that?) then you lay the DriCore panels down and THEN you lay the PLYWOOD over the DriCore....and THEN you nail down the hardwood. Whew! Or you can look at engineered floating hardwood over a vapour barrier (there it is again) and a BEAUTIFUL cork underlay....like 1/2" cork would be AMAZING! As you can see, I will try EVERYTHING I possibly can to AVOID this type of subfloor system you are talking about. And I mean $5000 - $10,000 MORE to get away from it! That's how much I HATE the system you mentioned. Make sure your builder does everything properly (concrete patch, etc) and offers a LONG warranty on that subfloor system. Like 5-10 years (s/he won't like that ONE BIT). If s/he won't do it, then perhaps you would like to look at a different system.

SJ McCarthy, our contract is stated we are responsible for the materials and we pay for the labor. Unfortunately we never met nor discuss with the owner but only discussed in details ( in the proposal) with the project manager who is the solely the carpenter.) We just found out there were a lot of the DETAILS from the proposal were not explained (per the PM,but who knows) in detail to the owner or almost like "bait and switch" - for example like item #2- he spent more time because the owner did not get him another helper to help him- I told him this should not be the customer's expenses-Anyway we are willing to pay for it. The owner was offering to renew and establish a new contract from the original contact ( we felt that he cherry picking the items from the proposal, we marked them up then again he decided not to included) for the unfinished works . Once he agreed in our 2nd meeting (another example: he agreed tiling our study room to be included from the original contact in our 1st meeting then when he write the REVISED CONTRACT- he wants to charge us ), but again we are facing the same old stories-he tried to change the wording. We were burned so many times and now we diligently review line by line knowing the owner's personality. He kept saying he lived by the contract-then I told him then he should honor the low estimated to install our engineering hardwood floor including removing the carpet-in the end he says he would honor but he did not including the cost in the new REVISED contract which we add into it - we are so tired with his games. So now we put a contingency - once we agree with the new contract, no more additional expenses from the previous work was done- and we do agree that we need to be notified first and need both signatures for additional expenses from the new contract. and no more point finger of "not included" since we have discussed in detailed and are in the contract. The new addition has a hardwood floor installed - with Dri-core. Once hardwood floor was installed- they are some areas squeak- we were told by PM -put a marked up then he would fasten without explaining to us-these would be additional ridiculous charges (PM told the owner, too-we told PM that they should explain it to us- ) Regarding the installing the engineering hardwood floor is for our existing rooms(concrete slabs that has plywood already)- we are told just to put a vapour barrier. Is it possible to let me know what brands for the glues have to be moisture resistant ($2/sf) or moisture PROOF ($3/sf).? The manufacture instruction suggests to use Franklin Tongue and Groove adhesive (cross linking polyaliphactic emulsion glue) www.titebond.com -any suggestions? This Applachian engineering hardwood floor - FLOATING only needs GLUE between the wood (tongue and groove per the manufacture manual ) then would be FLOAT - this is not to be GLUE DOWN on our concrete floor (could be glue down if necessary but not in our case). Here is the website- on PAGE 9 http://www.appalachianflooring.com/uploads/general/documents/engineered-installation-guide.pdf We trust the PM and we pay for it- we just want to move on and complete the project-It has been almost 10 months. We have to do what we have to do to protect ourselves now- The owner refuses to install our towel bar in our new shower without charging us, and we told him we will take care them by ourselves. I will update this post and hoping for a better solution. Thank you