Hello All,

This is my first attempt at asking a question on the forum, as I’m a new member last month. My wife and I live in Southern California, climate zone 3, and are building an attached, slab on grade ADU. In order to save on material costs here and there, as well as reuse materials, I was thinking of using the large roll of leftover 6mm visqueen that we used as an underslab vapor barrier as the laminate flooring underlayment. Most of my searching has only yielded results concerning wall assemblies, but I couldn’t find anything related to using it underneath flooring. Am I setting myself up for trouble or is this okay? What specifications would I look for in comparing the vapor permeability of visqueen versus a branded, specific flooring underlayment?

Thanks