insulit Bi+8

Foam + felt, comfort and security 28 dB

The underlay for a superior acoustic comfort between floors

insulit Bi+8 is an acoustic underlay designed to limit the transmission of impact and airborne noise between floors. Building on the success of the insulit Bi+7, we wanted to obtain with its successor, the insulit Bi+8, an even easier installation of the product. We also wanted to develop a much more resistant product with an improved acoustic performance.

This new product belongs to our premium range. Recent tests carried out by the BBRI according to EN ISO 717-2 are proving its outstanding performance. If installed on a concrete slab, under a floating screed of ± 6 cm thickness, it is possible to measure a ∆Lw of 28 dB! To achieve even better results, we recommend using a thermal levelling screed.

Foam + felt: unique acoustic performances!

insulit Bi+ 8 is made of an embossed, physically crosslinked polyolefine foam (thickness ≥ 3,5 mm) with closed micro cells, combined to an acoustic felt with a low dynamic stiffness (thickness ≥ 5 mm). A bi-component underlay is far more efficient than a single layer acoustic solution: the foam and the felt altogether are able to cover a much larger frequency range, where the felt absorbs low frequencies and the foam absorbs medium and high frequencies.


  • Reduction of impact & airborne noises
  • In rolls, quick and easy installation
  • Highly efficient
  • Tape provided to maintain the overlaps
  • Physically crosslinked polyolefin: guaranteed longevity
  • Closed microcells
  • Thin, light and flexible
  • Low dynamic stiffness = better acoustic performance
  • Low creep
  • Recent BBRI reports = guaranteed good results



Physically crosslinked polyolefin
and acoustic polyester felt


≥ 8,5 mm under 1,5 kPa


Orange (foam) / Anthracite (felt)

Impact noises insulation:

ΔLw = 28 dB on a bare slab with no pre-screed
(ISO 717-2:2013 ; EN ISO 10140-3:2010)

Dynamic stiffness:

st = 8 MN/m³ (EN 29052-1)

Tear resistance:

50 – 50 N (EN 12310-1)


≤10 % under 2 kPa (tolerance 10%)

Thermal resistance:

R = 0,26 m²·K/W (EN 12667:2002)

Thermal conductivity:

λ = 0,0356 W/m·K at 10°C (foam) (EN 12667:2002)
λ = 0,0353 W/m·K at 10°C (felt) (EN 12667:2002)


30 m x 1,50 m = 45 m²


±320 g/m² (15 kg per roll)


±15 kg


Junction is made with an included kraft tape

Datasheet insulit Bi+8 Read online Download