Underlayment is a modern subfloor under the parquet floors. Underlayment is made out of two layers of solid polythene with flexible polystyrene granules between the layers.
This structure makes underlayment a clean, durable and lightweight material that is easy to handle and install. Underlayment provides a highly effective double moisture barrier against subfloor humidity, obviating in most cases the need for a separate moisture barrier.
Prior to installation remove any dirt and dust from the subfloor. Roll out a strip of the underlay on top of the subfloor in the roll’s unfolding direction, face-down, leaving a gap of 5 mm between the underlay and the wall. Underlay can easily be cut with any knife for example a stanley knife. Be careful that you don't damage under floor heating system if there is any.
The adjacent underlay strips are connected together end-to-end, covering a junction with the special overlap (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 underlayment strips are tightly adjoined, and the overlap is firmly on top of the junction. Be careful not to damage the underlayment when moving on top of it: avoid puncturing and denting.
For Polarwood hardwood floor installation we recommend “Antishum Etalon” underlayment.