Before installation make sure that the subfloor is clean, dry and level. The relative humidity of concrete floors must be under 85 %. Check that the floor surface is level with e.g. a ruler or a straight floorboard: - max 3 mm deviation allowed over a length of 2000 mm. Where necessary level out the subfloor, using a good quality levelling compound.
Prior to installation remove any dirt and dust from the subfloor. Roll out a strip of the underlay on top of the subfloor, leaving a narrow gap (appr. 5 mm) between the underlay and the wall.
Tuplex underlayment is installed onto the subfloor according to the roll's unfolding direction, face-down. Tuplex can easily be cut with for example a stanley knife. Be careful that you don't damage the materials underneath, such as under floor heating systems.
The parallel strips are joined together with the plastic overlap, by turning the plastic onto the previous strip (by width of the overlap, about 20 cm). The successive strips can also be taped together if so wished, but it is not obligatory. Taping helps keeping the underlayment in place during hardwood floor installation. Make sure that the Tuplex strips are tightly adjoined and the plastic overlap firmly on top of the seam. When moving on top of the underlayment, avoid puncturing and denting of the Tuplex.