Cavity Stop Sock

Fire-Rated Cavity Barrier for Masonry Construction

Key Facts:
  • Up to 4 hours fire integrity
  • Horizontal and vertical options
  • Specified in terraced, semi-detached, apartments and major projects
  • Meets requirements of Approved Document B
  • Maximum cavity width available: 300mm
  • Simple installation; no mechanical fix required
  • Third-party certificated by IFC
  • CCPI assessed

Speak to an expert

Get in touch today to discuss your requirements and learn more about our Cavity Stop Sock
Description:

The ARC Cavity Stop Sock is a fully tested IFC certificated cavity barrier purposely designed to stop the spread of heat and flames in the external wall cavity of low-rise construction. The Cavity Stop Sock has been rigorously tested to meet or exceed the performance requirements laid out in UK and Irish Building Regulations, helping to ensure safer homes. It can be installed horizontally or vertically at the party wall detail.

Key Stats
Key Stats LabelKey Stats Value
Length supplied 1.2m
Third party certification Cavity Stop Sock: IFC certificate number: IFCC 1727 - Party Wall Cavity Stop Sock: IFC certificate number: IFCC 1728
Fire rating Up to 4 hours
Insulation performance Minimum 15 minutes
Insulation Rockfibre mineral wool
Thermal conductivity 0.037W/mk
Cavity widths available Masonry
Test standard EN1366-4
Orientation Horizontal or vertical
Mass Data available on request

Key Benefits

Third party certificated

CCPI assessed

Exceeds performance requirements

Horizontal & vertical applications

Application:

ARC Cavity Stop Sock restricts the spread of flames within the cavity of external masonry walls. It is ideally suited for providing a cavity barrier within the external wall cavity, in line with a separating wall or floor as specified in Approved Document B, and for closing the cavity at eaves level. The person installing the Cavity Stop Sock should first familiarise themselves with the datasheet, ensuring the correct product is being fitted into the cavity.

All performance claims made are evidenced in the IFC certifications IFCC 1727 & IFCC 1728.

Test reports, third party certification and MSDS available on request.

Would like to know more about our Cavity Stop Sock?

Get in touch today to discuss your requirements and learn more about our Cavity Stop Sock. Our dedicated team is ready to collaborate with you from the initial consultation through to project completion, ensuring every detail is handled with expertise and care.
Installation instructions

ARC Cavity Stop Sock is designed to be simply compression fitted as the brick and block work progresses. No mechanical fixing is required, with the compression fit holding the barrier in place. Care should be taken when handling the product to ensure that the mineral wool isn’t damaged. The person installing the ARC Cavity Stop Sock should first familiarise themselves with this datasheet, ensuring the correct size of product is being fitted into the cavity.

The barrier must fully fill the cavity from external brick to internal block. Any cavity insulation must be cut back at the location of the barrier, and care must be taken to ensure that the built cavity width is accurate and that the size of barrier fitted is appropriate to this. 

  • Vertical application: we recommend building up the internal block work first. Then progress several courses of brickwork, before installing the barrier. The brickwork can continue, building the barrier in. Care must be taken to ensure the correct compression fit is achieved. 
  • Horizontal application: build the brickwork up to the level the barrier will be installed, ensuring the width of the cavity is correct. Allow the brickwork to set, before push fitting the barrier in to place and under the correct compression. 
  • At the end of a run, or at a corner, lengths of barrier should be cut to the required length, and then tightly butt jointed ensuring no gaps remain. 
  • The polythene encapsulation does not contribute to the performance of the barrier, but offers weather protection and product identification. We recommend that it is left in place for these purposes, however if it becomes torn or damaged there is no cause for concern. 
  • You should not attempt to squash the barrier before installation. Although this can make the barrier easier to fit, it is likely to cause gaps and may damage the barrier, resulting in reduced performance.

FAQ’s

Can ARC Cavity Stop Sock be used around window and door openings?

ARC Cavity Stop Sock will provide fire and thermal properties when used around window and door openings. You will need to consider moisture penetration in your design as the product does not include an integral DPC.

Can this product be used with an SFS internal leaf?

ARC Cavity Stop Sock is fire rated and certified for use in a traditional masonry construction.

How do you install the ARC Cavity Stop Sock?

Please follow the guidance on our datasheet and within our product video.

Do I take it out of the coloured sleeve?

The polythene sleeve is there to provide product identification and protection from the elements and should therefore be left in place. It does not add to the performance of the product so can be safely cut in to, and the product can still be used should the polythene be damaged.

Do you have to install a separate DPC or cavity tray?

The product does not include an integral DPC. A separate cavity tray or DPC should be installed where this is required by the location or type of building.

Can this cover multiple cavity sizes?

ARC Cavity Stop Socks are designed to suit specific cavity widths and are available in 5mm increments. It’s important that the appropriate size is fitted to achieve the required compression fit and to ensure the product performs as expected.

Do you have further documentation for the Cavity Stop Sock?

For any information not found on the datasheet, please contact our technical team for support. Test reports, third party certification and the material data sheet are all available on request.

Related Products

Speak to the Specialists

Our team is here to help you with your high performance fire protection...

For support or more information, contact a member of our expert team. We’re available to speak with Monday to Friday, 8am – 5pm. For technical enquiries including legacy product information please call 0113 252 9428 and select option 2.

Complete the form provided and we will get back to all enquiries as soon as possible.