We are getting ready to install Coretec Plus in our basement. I know we'll need a moisture barrier on the concrete as a security measure before we lay down the floor. But, should we also use an additional underlayment or some kind of 2-in-1 underlayment? There is already the attached cork. Floor & Decor has their Sentinal Protect Plus underlayment I was considering. Coretec allows the 6mil poly + less than 3mm of underlayment if you are going to add. Has anyone installed Coretec Plus? How did you do it? THANKS!