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.
Underlay mats should be laid grooved-side down, with an offset of 50 cm between adjacent rows, and the distance between the edges of adjacent mats should be no larger than 2 mm.
Mats should be stabilised in spots with adhesive tape.
The underlay should be laid at a 45° angle to the direction the floor panels will be laid in.