I'm installing Lumber Liquidators' Morningstar XD bamboo laminate flooring in my basement. According to their tech support, they have the following flatness requirements for the underlayment:
(1) no more than 1/8" over 6', and (2) no more than 3/16" over 10'.
A contractor friend thought that sounded excessively stringent. And to meet those requirements I'd need to smooth out the existing concrete floor, so I want to be sure.
Are those tolerances overkill?
Best Answer
It's really hard to provide objective advice. There are many factors, and the shape of the irregularities is critical.
It would take a booklet to lay it all out. I'd stick with mfr specs + maybe 25%.