Staff Answer
Jul 11, 2025 - 11:47 AM
We always suggest and follow what Forbo says in their installation guide : https://www.greenbuildingsupply.com/c... "Marmoleum Cinch LOC Seal can be installed on any clean, dry, structurally sound subfloor. The subfloor must be flat to within 3/32" in 6' (2.0mm in 2 meters). " It is best practice to go by the actual manufacturer words. According to the QuietWalk Plus installation : https://www.greenbuildingsupply.com/c..." . If the flooring manfuacturer does not specify requirements for flatness, your subfloor must be flat within 1/8" over 6' span, or 3/16" over a 10' span. All leveling, prep work, priming, etc must be done prior to installation of underlayment."
