bc is right. I, too, believe the best thing to do is contact Pergo. Aside from your question, if you don't do what they recommend, you could VOID your Warranty.
Also, Pergo is a floating floor. Since this is the case, it will sound hollow when you walk on it, especially with concrete underneath. (Sound doesn't travel real well through concrete.)
My best to ya and hope this helps.
PS: There is no 'padding' for Pergo, per se.
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