
Recently bought a bunch of these Prima ceramic tile underlay boards from Bunnings in two separate purchases. It’s my first time using them so I have not experienced how they may vary across batches.
https://www.bunnings.com.au/hume-prima-ceramic-tile-underlay-1800-x-900-x-6mm-1-62sqm_p0710334
The boards from one purchase are much heavier and darker in color than the boards from the other purchase. Color difference is shown in the pic. Not concerned about color of course, but the heavier boards feel much more heavy duty and sturdy so am concerned about performance. The boards both have exactly same print on back identifying what they are and they share the same manufacture date too. I could imagine some slight differences in batches that are manufactured, but noticeably different weight seems very odd. Is variation such as this usual, or is it possible the lighter boards were cut and labelled as tile underlay boards in error?