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Acoustop Cavity Stop Socks

Thermal and acoustic 60 minute fire rated fire stops for installation within external cavity and timber frame walls to:

  • restrict the spread of smoke and flames
  • minimise the effect of flanking noise at wall junctions.

Acoustop Cavity Stop Socks are lengths of low resin, non-combustible Rockfibre mineral wool, sleeved in 50 micron polythene for on-site weather protection.

Designed to friction fit within the cavity and can be installed both vertically and horizontally during construction.

  • Supplied as standard in 1.2 metre lengths to suit cavity widths of 50, 75, 85, 100, 115 and 125mm
  • Flanged Stop Socks are also available for timber frame applications.

For more information call 01405 765567 Free next day delivery *

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Features & Benefits

  • 60 minute fire integrity
  • Encapsulated in polythene for on-site weather protection
  • Can be installed vertically or horizontally
  • Class O surface spread of flames
  • Available to suit a wide variety of standard cavity widths
  • Non-standard cavity widths can be made to order



  • cavity wall constructions
  • timber frame walls.

Technical Information

Thermal conductivity of Rockfibre insulation is 0.037W/mK.

How to Order

How to calculate the required quantities:

  • divide the overall length of the required cavity wall run by 1.2 metre (product length).
  • allow an additional unit for each corner for cutting.
  • always round up to the next whole number

Please stipulate the cavity width that the Acoustop Cavity Stop Sock needs to suit with all enquires and orders. Can only be purchased in pallet quanties. Ask a member of our team for more information.

Installation Advice

Timloc cavity socks are designed to friction fit within the cavity and are easily installed both vertically and horizontally into the cavity during construction.

Care should be taken to ensure that butt joints are closely fitted and the cavity sock fully fits the cavity.

This method should be incorporated with a performed horizontal cavity tray proprietary wall weep vents at 900mm centres, to prevent water ingress from bridging across the cavity.

Please contact the Timloc Technical Team for further advice regarding the installation process for Acoustop Cavity Socks and any other of our products.

Quality, Regulations and Standards

  • Satisfies all relevant NHBC standards
  • Meets the requirements of the Robust Detail
  • Complies with Building Regulation Document Part B
  • And all other relevant Building Regulations
  • Non-combustible to BS476: Part 4 Class 1
  • Surface spread of flame to BS476 part 7 1987
  • Class O to the Building Regulations

Material and Colour Choice

  • Manufactured using Rockwool mineral wool
  • Rockfibre uses no CFC’s or HFC’s in the manufacturing process
  • Thermal conductivity of Rockfibre insulation 0.037W/mK
  • 50 micron polythene weather protection sleeve
  • nbs plus
  • riba

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