It is not recommended but I was successful in using under hardwood over a uneven plywood subfloor. The subfloor needs to be primed first, otherwise the moisture will be sucked out of the levelling mix, and it will not flow. I used a 10’ metal stud as a screed, and pulled it across the room to ensure smoothness as without screening, the leveller may leave slight ridges.
The leveller dries as cement, quite hard and brittle. If the leveller is greater than 1/4”, the hardwood staples have difficulty penetrating. I had some which deflected and curved and required careful extraction. Also some flooring boards were damaged as a result.
I used roofing tar paper over the levelling compound and under the hardwood. In the end I was able to successfully install 500 sq feet of acacia wood flooring. Installed for 3 years now without squeaks.
Date de publication: 2021-03-19