RainScreen Cavity Systems

Thames Quarter, Reading

Your complete rainscreen cavity system

Ready to streamline your rainscreen specification? 

There’s no need to waste time sourcing insulation and cavity barriers from multiple manufacturers, comparing credentials, and researching compatibility.  

Now you can get a complete, fully tested cavity system from Knauf Insulation. Our trusted Rocksilk® RainScreen Slab insulation, paired with our new range of cavity barriers, will help you streamline your specification process whilst meeting the relevant Building Regulations.  

Our solution for masonry façades also features our innovative cavity barrier, Rocksilk® RainScreen FFCB. Because it can be fixed to the face of the sheathing insulation, Rocksilk® RainScreen FFCB takes approximately half the time to install properly* vs. traditional cavity barriers. 


For straightforward specifications and reliable results, choose a Rocksilk® RainScreen Cavity System.


*Based on a single, timed installation of Rocksilk® RainScreen FFCB, alongside a traditional cavity barrier.  

What’s the best system for your build? 

We offer Rocksilk® RainScreen Cavity Systems for both cladding and masonry façades. Every system includes our trusted rock mineral wool insulation, Rocksilk® RainScreen Slab. It’s non-combustible, with a Euroclass A1 reaction to fire classification, and holds an Agrément certificate by the BBA (certificate 19/5609) for use in multiple build-ups. 

Our Rocksilk® RainScreen Cavity Systems can be used with the major substrate types, including blockwork, steel, and timber: 



Our system for rainscreen façades with a 

Cladding outer leaf

Our systems for rainscreen façades with a 

Masonry outer leaf


Rocksilk® RainScreen Slab

Rocksilk® RainScreen Slab

Cavity barrier options:


  • Rocksilk® RainScreen OSCB or; 
  • Rocksilk® RainScreen OSCB Plus
  • Accompanying fixings 


  • Rocksilk® RainScreen FireStop Slab 
  • Accompanying fixings 

Horizontal + Vertical:

  • Rocksilk® RainScreen FFCB
  • Accompanying fixings


 System tested to ASFP TGD-19 and EN1366-4 System tested to EN-1366-4 and assessed by UL Solutions 

Note: Rocksilk® RainScreen OSCBs and Rocksilk® RainScreen FireStop Slab can also be used with some masonry façades, depending on the requirements of the build.

The right combination of insulation and cavity barriers will depend on the details of your construction and your specific fire safety requirements. For example, our systems consist of sheathing insulation, fixings, and cavity barriers providing between 30 and 180 minutes fire resistance.

For advice on the right Rocksilk® RainScreen Cavity System for your project, speak to a member of our Specification Team.

You can find your nearest Knauf Insulation contact by using our Contact Finder tool