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Thermo-loc Vertical Cavity Barrier

Fire-rated acoustic cavity barrier and DPC.

Use cases:

  • Effectively reduces the transmission of flanking noise at party wall and external wall junctions
  • As a fire stop with integrated DPC

For more information call 01405 765567 Free next day delivery *

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Features & Benefits

  • The Thermo-loc vertical cavity barrier has been developed to offer vertical protection in minimising flanking noise transmission along the cavity of an external cavity wall at the intersection of a party wall. The product also operates fully as an effective fire barrier and in conjunction with the polythene DPC has no risk of water penetration.
  • Where a party wall meets the cavity wall, Building Regulations stipulate the use of a mineral wool closer for sound insulation purposes. The NHBC requires that any such closer is protected by a suitable DPC. The product has been developed to meet these requirements.
  • Complies with Building Regulations Part E & B
  • Excellent sound insulation properties
  • As a fire stop achieves 4 hours (240 minutes) fire integrity to BS 476 Part 20:1987
  • Cavity options available
  • Self supported by compression fit
  • Easily installed


Technical Information


  • Satisfies all NHBC requirements
  • Complies with Building Regulations Part E ‘Resistance to the passage of sound’
  • Complies with Building Regulations Part B ‘Internal fire spread (structure)’
  • Complies with Robust Details

Material and colour choice

  • Manufactured with BS6515 Polythene DPC
  • Supplied in 1.2 metre lengths
  • Cavity options available
  • Rockfibre insulation slab
  • 260mm width insulation

Installation advice

  • Installation must follow good practice for the detailing of damp proof courses, as set out in the relevant clauses of BS 5628: Part 3, BS 8215 and BS 8000: Part 3.
  • The product should be built in as brickwork/block work proceeds.
  • The DPC projects beyond the insulation by 50mm on each side and should be installed to compress against the inside face of the outer leaf.
  • Supplied in 1.2mtr lengths of insulation with an additional 100mm overlap of DPC and to cavity size required. Units easily cut on site for detailing.
  • Where more than one length is required, joining lengths is by simply butt jointing together. The upper piece must be installed with the 100mm DPC extension at the bottom, lapping to the outside of the lower piece ensuring a tight butt joint of the insulation.
  • Vertical protection is given without breaks at floor level
  • Due to the flexible nature of the rockfibre insulation some local delaminating may occur during site handling or installation.
  • This does not detract from the performance of the product.

Bill of quantity

F30 Accessories/sundry items for brick/block/stone walling

  • Manufacturer: Timloc Building Products, Timloc House, Ozone Park, Howden, East Yorks. DN14 7SD. T: 01405 765 567, W:
  • Type(s) and location(s): Fire-rated acoustic cavity barrier & dpc to be installed vertically as work proceeds. Position vertically where a party wall meets the cavity wall, supplied in 1.2 mtr lengths and butt jointed.
  • Reference: VACS Range

VACS50 – 50mm cavity
VACS65 – 65mm cavity
VACS75 – 75mm cavity
VACS85 – 85mm cavity
VACS100 – 100mm cavity

  • nbs plus
  • riba

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