insulit Bi+20

All in one: thermal and acoustic insulation 29 dB

The all in one underlay for screeds: thermal and acoustic insulation

insulit Bi+20 is a new acoustic AND thermal underlay exclusively dedicated to floating screeds. This underlay has been designed not only to limit the transmission of impact noise between the floors of a building, but also to provide thermal insulation under the floorings. The insulit Bi+20 underlay has to be laid under a ± 8 cm thick floating screed.

insulit Bi+20 offers many benefits: it saves material and application time by placing an all in one solution. Moreover, this single underlay reduces the overall thickness of the floor, the working time, and the operating costs.

installation of insulit Bi+20, the thermal and acoustic underlay for floating screed

A single layer is enough to meet the acoustic and thermal insulation requirements between the floors of a building !

The Bi+20 underlay benefits from thermal and acoustic reports after tests have been carried out following the criterias of the latest applicable norms.


insulit Bi+ 20 is made of physically crosslinked polyolefine foam with closed micro cells combined to an acoustic felt having a low dynamic stiffness. Joining these two layers increases the acoustic insulation level:  the foam and the felt altogether can cover a much larger frequency range. The felt decreases low frequencies while the foam decreases medium and high frequencies.


  • All in one : thermal and acoustic insulation
  • Light and flexible, quick and easy to install
  • Duck tape included to seal off the edges
  • Physically crosslinked polyolefin with closed micro cells
  • Low dynamic stiffness
  • BBRI & Eco-scan – 2015 reports = guaranteed good results
installation of the insulit Bi+20
  • BBRI
  • VOC
insulit Bi+20 thermal and acoustic underlay for floating screed
insulit Bi+20 thermal and acoustic underlay for floating screed



Physically reticulated polyolefin and a polyester acoustic felt


≥23 mm (EN 823)


Grey (foam) / anthracit (felt)

 Impact noise insulation:

Δ Lw = 29 dB (EN ISO 717-2:2013 – EN ISO 10140-3/2010)

Dynamic stiffness:

st ≤ 7 MN/m³ (EN 29052-1)

Tear resistance:

43 – 46 N (EN 12310-1)


≤ 5% under 2 kPa

Thermal resistance:

Rd = 0,65 (m²·K)/W (EN 823:2013)


20 m x 1 m = 20 m²


± 700 g/m² (14 kg per roll)


Junction is made with an included duck tape

Datasheet insullit Bi+20 Read online Download