Get someone in there to scarify the slab to remove the aqdhesive residue and anything else that may be a potential bond breaker. Then, test for moisture vapor emissions and, if appropriate (probably will be), have a moisture vapor transmission sealer or membrane installed and glue your product over that.

There are product 'systems' designed for the situation you describe. Bostik is only one brand of many manufacturing such a system. If I had more time, I'd tell you more, but you'll have to do this research on your own...or maybe someone else will give you some links to try.

Good luck.

Parquet shorts is much different then strip or plank flooring!!

Tread lightly!! Solid over concrete is a big risk. The guys suggesting an engineered are heading you down the right road.

There are many glue manufacturers that are boasting of what their glue can do. Read the warranties, and what they actually replace and warrant. A few replacement buckets of glue, is not going to buy the expensive firewood.

Eiter way is fine, but plywood would be the best alternative with the engineered installation over concrete.

It is more expensive but the insurance company is paying for it so let the professional do it how they feel is best for your situation.

Thanks for the feedback from all of you.

Directed to FloorGuys's comments: I think we are all in agreement that solid wood is out and engineered is in.

For everyone: I am just trying to make sure that the concern of gluing to a concrete subfloor which has cutback adhesive residue is justified. I would prefer a straight glue down to the concrete but the installers seem really concerned about this. My situation seems fairly unusual so perhaps they are just not up to speed on what the various glues can do?

Should I not even worry about the above and just accept the proposal of putting down a 1/2" plywood subfloor and gluing engineered to it? Are there any problems with rot of the plywood floor under the egineered product? Will this floor feel solid versus the way a floating installation feels?

Thanks again everyone.

Cutback adhesive can penetrate into the concrete and can be problematic and time consuming to remove, which is probably why they are suggesting the layer of plywood. Also, it can have a negative reaction with other adhesives. Meaning other adhesives might have trouble sticking to it. Combine that with its possible penetration into the concrete then you may have issues if 100% of your existing adhesive isnt removed if they didnt use plywood. It is virtually impossible to remove 100% of cutback adhesive out of porous concrete, even if you grind the concrete becasue it can penetrate into it. You can not tell that until you scrape it downand try to remove it.

I think your installer is trying to give you the best job possible here.

If you paid them an hourly prep rate to remove the adhesives completely from the concrete, the costs could be as much or more than the plywood itself.

As to rotting, they you stated they are isntalling a vapor barrier ?

yes ?

then this should not be an issue, but they should nevertheless be performing moisture testing to be sure moisture is at or below acceptable levels.

as to the solid sound, it should feel solid with plywood under it unless there is excessive waviness and high spots the plywood will span, and they do not correct it by grinding or patching/screeding, of course that would be more money to prep your floor if there are.

Thanks for the feedback. Yes, they are either going to use a 1/2" plywood with a vapor barrier below and glue above or 1/3" plywood which will be glued and nailed down followed by the product glued to the top of the plywood.

One installer felt the first way was the best way to go to avoid the thinner plywood causing problems, the second installer said that by gluing and anchoring the thinner plywood they would avoid any problems.