Here is an article that might help you - https://www.thespruce.com/laminate-flooring-underlayment-1314969
Hi Sheila, Foam is the most basic laminate flooring underlay. The foam is 3mm (1/8”) to 6mm (1/4”) thick and comes in rolls of various widths and lengths. There are two types of foam underlayment – combination laminate underlay with an included moisture/vapor barrier and foam with no barrier.
Sheila, you cannot as it is too spongy and thick, Why Can't I Use Carpet Underlayment? Put simply,carpet underlayment is too thick. Most laminate flooring underlayment is 1mm to 3mm thick. ... If you reuse your thick carpet padding, your floor willbe too bouncy and it may damage the locking system.
Hi Sheila! I've found that when looking at flooring, that each manufacturer has specific underlayment requirements. If you don't install it correctly, it may void your warranty.
Thank you for your clarification. I really appreciate it.