Rocksilk® RS100 Building Slab


Suitable for use in a variety of thermal and acoustic applications including in ground floors, internal floors, separating floors, fabrication, pitched roofs at rafter level, internal walls/ partitions, light steel frame walls and timber frame walls.


Rocksilk® RS100 is a Rock Mineral Wool slab, designed for use by fabricators in specialist applications where density and mechanical characteristics are critical (such as passive fire protection).

It is non-combustible with the best possible Euroclass A1 reaction to fire classification, and is manufactured using Knauf Insulation's unique bio-based binder, ECOSE® Technology.

Features and benefits:

  • Good thermal performance.
  • Non-combustible A1 Euroclass Reaction to Fire classification.
  • Good sound absorption characteristics provide high levels of sound reduction.
  • Multi-purpose product range which can be used to insulate a wide range of applications on site.
  • Available in a wide range of densities to suit a variety of uses, applications and performance requirements.
  • Easy to cut with a large bladed knife or saw.
  • Can be provided with a factory applied foil or tissue facing, offering solutions for a wide variety of applications.
  • `A` generic BRE Green Guide rating.

Product reference:

The product is supplied un-faced, but it can also be manufactured with a factory applied foil or tissue facing and is also available in a water repellent grade.

General information



Tissue Faced

Foil Faced



Rock mineral wool.




1200 x 600 x 30 mm

Uniclass 2015

Pr_80_77_76_53 Mineral wool duct slab insulationPrimary


H11/780 Thermal insulation

P10/250 Insulation supported between floor joists

P10/50 Insulation supported between joists

Specification data - Mineral wool duct slab insulation Enhanced data


BS EN 13162.

Thermal conductivity

0.034 W/mK.



Tissue Faced.

Foil Faced.

Reaction to fire classification

Euroclass A1 (non-combustible) to BS EN 13501-1.

Insulation thickness (minimum)

25 mm.

30 mm.

40 mm.

50 mm.

75 mm.

100 mm.

Vapour barrier


Vapour permeability

5.00 MNs/g.m.

Product Reference

Earthwool® Building Slab RS100

Earthwool® Building Slab RS100 Foil Faced

Earthwool® Building Slab RS100 Tissue Faced

Earthwool® Building Slab RS100 Water Repellent Grade

Environmental information

Country of material origin

United Kingdom


BRE generic Green Guide rating of A.


Digital objects

Platform Compatible Version Certified to




Download now from NBS National BIM Library


Knauf Insulation Rocksilk® Acoustic Floor Slab Insulation Data Sheet

Knauf Insulation Rocksilk® Acoustic Floor Slab Insulation Data Sheet

Third party certifications

  • Eurofins Gold Certificate for Indoor Air Comfort

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