The requirements for how flat a floor must be before installing a floating floor can vary depending on the type of flooring being installed and the manufacturer’s guidelines. However, as a general rule of thumb, the subfloor should be flat to within 3mm over a 2-meter radius.
If the subfloor is not level, it may be necessary to prepare it before installing the floating floor. This can involve using a leveling compound or self-leveling screed to even out any high or low spots. In some cases, a plywood subfloor may need to be installed over the existing subfloor to create a level surface for the floating floor.
It’s important to follow the manufacturer’s guidelines for the specific type of flooring being installed to ensure a successful installation and avoid any warranty issues. Additionally, it’s a good idea to consult with a flooring professional to ensure that the subfloor is adequately prepared for the floating floor installation.