On Tuesday, May 9, 2017 at 5:18:09 PM UTC-4, Andy wrote:



Underlayment is a plywood that is 1/8 inch thick.

Not so.

While it is true that 1/8" plywood is often used as underlayment,
"underlayment" is not any specific size or type of material.

https://en.wikipedia.org/wiki/Underlayment

https://www.lowes.com/pl/Flooring-un...ing/4294418636