Before laying the underlay, the cement underlay needs to be isolated with 0.2 mm thick, quasi-isolating foil.
The base should be clean, dry, and even.
An underlay should be laid grooved-side down, and the distance between the edges of adjacent rows should be no larger than 2 mm.
Underlay rows should be stabilised in spots with adhesive paper tape.
An underlay should be laid at a 45° angle to the direction the floor panels will be laid in.