I installed an engineered Brazilian Cherry back in July 2011. I had to use some screed (Mapei Planipatch with latex) and glued the wood with Mapei 980 adhesive and the wood is breaking bond from the substrate (concrete slab). The planipatch is stuck to the wood but leaves a bone dry substrate. All of the planipatch comes up stuck to the wood, nothing stays on the slab. The previous floor was also an engineered brazilian cherry that was very difficult to take up. I do take up and installations on a daily basis but had never seen anything like this. I do notice an odor coming up from the slab as if it has some kind of solvent/ residue yet visibly there is nothing present. Has anyone seen anything like this? Replacement is imminent yet I don't want the same result in the future. Please advice.

My advise is to check for any bond breakers on the slabs surface. There must be a reason for the planipatch breaking off. Was there adbesive residue on the surface from the old install? Was it just scraped off or mechanically removed prior to the installation of the new wood floor?

I've heard of people touting the bonding ability of planipatch to adhesive residues being as good or better than Ardex Feather Finish but never went that route.

The old floor was manually scraped up. This method will usually leave a clean, residue free surface. Now, I suspect that the old adhesive penetrated into the slab and there may be still a film of the old adhesive that even though is not visible, it is not letting it adhere to the planipatch/ planiseal mix. As I mentioned, I probably use between 20 to 30 bags a week of planipatch/ planiseal per week and this is the first time that I come across this issue. Do you recommend a mechanical method to make the surface bondable again?