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Flexible Sponge Rainscreen Cavity Barrier (RSF)

Product 55


[ RSF ]

Moisture resistant rainscreen cavity barriers designed with intumescent fireproof sponge instead of mineral fibre. Washers and screws are also supplied.

Not available to purchase online.

We need to ask you a few more questions and ensure this is the suitable product for your needs.

To order please call us on +44 (0) 1 304 842 555

£0.00 ex. Vat



Flexible Sponge Rainscreen Moisture Resistant Cavity Barrier

Flexible sponge rainscreen moisture resistant cavity barrier range, especially designed to offer excellent passive fire protection for rainscreen and other types of cladding.

Using fireproof sponge instead of mineral wool, this range offers many advatanges:

  • The barrier is much thinner, additionally offering a better fire rating.
  • Easy to fix and no masks required.
  • Fixing brackets already in place, fix with screws, nails, or spit nails.

Made in 1-metre lengths, with 4 fitting brackets for horizontal application or 3 brackets for vertical.

Cut with a sharp knife to fit around metalwork. Furthermore, the cover is made from a strong, intumescent-coated material, completely water-resistant.

The RSF range is the same as the RSM but with a foiled reinforced covering that is water-resistant.

Depending on the required fire rating, the barrier can have a different thickness. Specify the overall cavity size and required ventilation gap when ordering.

Cavity Barriers are pieces of fire-stopping material. They fit within the cavity of a building at each floor horizontally and party wall in a verticle position. The material provides compartmentation. Both the flames and heat cannot be transferred to other compartmental areas. Throughout the life of the building, the Cavity Barrier will remain fixed in place. In the event of a fire, the intumescent material expands and seals off the gaps. Additionally, the horizontal barriers allow for a ventilation gap within the cavity. Subsequently closing when the intumescent expands.

Our Cavity Barrier range at Envirograf® offers superb protection to your building by providing fire stopping. Explore the Cavity Barrier range online.


– Barriers have a slim profile without compromising fire rating.
– Non-fibrous, dust-free and easy to install with washers or brackets.
– The entire RS range can be fitted vertically or horizontally.
– Tested to BS EN 1363-1 (1999).
– Tested to BS476 Part 20, achieving up to 66 minutes protection.

Application Instructions

This barrier comes supplied with 4 fixing brackets which can be simply screwed, nailed or spit nailed to the internal wall (pre-drilled holes are suitablefor up to 12mm size screws).

Non-fibrous products used in this barrier makes it even easier to install. The barrier can be easily cut with a sharp knife or blade. If during installation you find wall imperfections, these can be filled with Envirograf Intumescent Mastic (Product 58).

Case Studies

  • RSM cavity barriers in a prestigious London project

    RSM cavity barrier used at Eagle House, 161 City Road, London

  • Living the High Life on Finchley Road

    Rainscreen cavity barriers used to protect concealed cavities between cladding.

Order References / Sizes

RSF RANGE                  30/60 minutes / Thickness   40mm

RSF Non-ventilated                                    1 metre long
Ref                                  Width
RSF150                          150mm
RSF180                          180mm
RSF200                          200mm
RSF250                          250mm
RSF300                          300mm


RSF/I with intumescent                            1 metre long
Ref                                    Width
RSF/I/150                       150mm
RSF/I/180                       180mm
RSF/I/200                       200mm
RSF/I/250                       250mm
RSF/I/300                       300mm


RSF/A with ventilation holes                   1 metre long
Ref                                     Width
RSF/A/150                      150mm
RSF/A/180                      180mm
RSF/A/200                      200mm
RSF/A/250                      250mm
RSF/A/300                      300mm


RSF with added moisture penetration protection

In some cases there may be a requirement for a perfect seal along the back fixing edge to seal and stop moisture penetrating down the back of the seal. We can supply the RSF range with a backing to stop the moisture penetration. The barrier has a strip of intumescent sponge along the back of the barrier that stops moisture from penetrating the seal. Also there is a sturdy metal strip built inside the barrier along the back to ensure there is a perfect seal. Can be added to all RSF barriers.

Add /MR to reference when ordering.