Cancel

Siderise TW Cavity Barrier and Firestop for Tops of Walls

Firestops designed to ensure compartmentation at the tops of compartment walls

Continue compartmentation 

TW Cavity Barrier and Firestop is designed for use within the joint between the top of compartment walls, partitions or fire-resistant suspended ceilings and the structural soffit. It features Lamella insulation comprising durable vertically oriented stone wool fibres which have been laterally pre-compressed under factory-controlled conditions and held with aluminium foil facings for reliable compartmentation and acoustic benefits. 

Up to 2 hours fire resistance

TW Cavity Barrier and Firestop is available in a variety of size options to cover gap heights between 20 – 400 mm, all with EI 30 to 120 options in accordance with BS 476-20

Qualified acoustic performance

The product provides tested acoustic performance with Weighted Sound Reduction Index values as low as 25 Rw (dB), helping to reduce room-to-room sound transmission

Accommodates building movement

The flexibility of the Lamella insulation core and its compression fit means it can flex and recover in line with any building movement

Related systems

Explore our other solutions developed for specific applications

Learn more
Application

Siderise firestops for tops of walls provide a seal between the top of the compartment wall, partition, or fire-resistant suspended ceiling, and the structural soffit. The choice of material is determined by the performance requirement in terms of fire resistance (i.e. insulation and integrity) and size of the cavity. 

Uses include: 

  • Fire-stopping voids above compartment walls and partitions up to 400mm dependant on fire performance 
  • As an acoustic barrier at tops of walls
Product Description

Siderise firestops for tops of walls comprise a single, close dimensioned product with a unique pre-compressed internal stone wool mineral fibre lamella core.  

The materials are manufactured using a unique manufacturing process to provide a resilient compression which ensures a tight fit. They are either supplied as pre-cut units to suit a quoted cavity size or in sheet form for cutting on site.  
 

The range of Siderise firestops for tops of walls includes various types of products which are referenced ‘TW’ to designate the ‘Tops of Walls’ application. The materials have been developed and tested at various thicknesses to meet the fire and acoustic performance requirements listed in Tables 1 and 3.


Fire Performance

In terms of ‘Reaction to Fire’, the products provide the following: 

  • Class ‘A1’, in accordance with EN13501-1

The design and manufacture of the range of Siderise firestops for tops of walls is based on proven fire performance to BS 476 : Part 20 :1987. 

Please note that Siderise firestops for tops of walls can be supplied for higher fire ratings and for voids greater than 400mm, up to 1200mm.  

The products have integral aluminium foil facings and are a functional smoke barrier.  
 

Table 1 - Fire performance and product sizes

Product Ref Void Width (mm) Thickness (mm) Compression (min.) Integrity (Mins) Insulation (mins) Product Length (mm)
TW-CB30
20 - 50
75
Gap Width +10mm
30
30
1200
TW-FS60
20 - 50
90
Gap Width +10mm
60
60
1200
TW-FS120
20 - 50
120
Gap Width +10mm
120
120
1200
TW-CB30
51 - 100
75
Gap Width +5mm
30
30
1200
TW-FS60
51 - 100
90
Gap Width +5mm
60
60
1200
TW-FS120
51 - 100
120
Gap Width +5mm
120
120
1200
TW-CB30
101 - 400
75
Gap Width +10mm
30
30
1200
TW-FS60
101 - 400
90
Gap Width +10mm
60
60
1200
TW-FS120
101 - 400
120
Gap Width +10mm
120
120
1200

NB: For bracket type and size please refer to Table 2

Table 2 - Fixing brackets

Bracket Ref. Min. Void Size (mm) Max Void Size (mm) No. of Brackets Bracket Centres (mm)
B65/110
50
150
2
600
B195
151
240
2
600
B355
241
400
2
600

Acoustic Performance

Siderise firestops for tops of walls provide excellent acoustic performance and can help to reduce room-to-room sound transmission. Their high performance is attributable to the mass of the stone wool core and the unique resilient lamella internal construction. 

In accordance with BS EN ISO 140-3: 1995, BS 2750: Part 3: 1995 the Weighted Sound Reduction Index (Rw) values shown in Table 3 can be used. 

These are based on laboratory tests for airborne sound transmission on a variety of lamella board constructions.  

The installation of the products above a partition will significantly increase room-to-room attenuation. The precise value will depend upon the specifics of the ceiling construction. Advice is available on a project basis.

Table 3 - Acoustic Performance (Weighted Sound Reduction Index)

Product Type Thickness (mm) Rw (dB)
TW-CB30
75
21
TW-FS60 *
90
22
TW-FS120
120
25

* =Rw value interpolated from test results 
Sound Research Laboratories Limited test report no. : C/99/SL/7743/I refers

Thermal Performance

Thermal conductivity : λ = 0.038 W/m.K (tested foil to foil)


Technical Specification

Siderise TW Firestops for Tops of Walls

Table 4: Product properties

Properties Value
Form supplied Sheets 1200mm x 1200m x thickness, Cut strips 1200mm x cavity + compression x thickness, See Table 1
Colour Silver, with coloured identification tape centrally located on product
Finish Aluminium foil
Density Nominal 75 kg/m3
Thermal conductivity λ= 0.038 W/m.K (tested foil to foil)
Cavities 20mm to 400mm
Reaction to Fire Class ‘A1’ to EN 13501-1
Resistance to Fire 30 to 120 minutes (integrity/insulation)
Environmental

The stone wool core is recyclable

Additional Information Available

The following information is available upon request or via download from the website: 

  • NBS Specification Clause 
  • Material Safety Data Sheet 
  • Cutting and Installation instructions
Technical Support

For technical advice or support please contact: technical.services@siderise.com 
 

For Installation Training or Site Inspections please contact: site.services@siderise.com


Context

The information in this datasheet is believed to be accurate at the date of publication. Siderise has a policy of continuous product improvement and reserves the right to alter or amend the specifications of products without prior notice. Siderise does not accept responsibility for the consequences of using the products described outside of the recommendations within this datasheet. Expert advice should be sought where there is any doubt about the correct specification or installation of Siderise products.

 

NBS Logo
Products

Ancillaries

Single source supply components for compatibility, performance and confidence

Siderise B Series Fixing Bracket
Siderise RFT Aluminium Foil Jointing Tape
Siderise Fire And Acoustic Gap Sealant

FAQs

Get quick answers to common queries or contact our team for more advice. Your questions answered.

Is TW Cavity Barrier and Firestop supplied pre-cut?

TW Cavity Barrier and Firestop can be supplied pre-cut or as a sheet for cutting onsite

What thermal performance can TW Cavity Barrier and Firestop achieve?

It can achieve thermal conductivities of 0.038 W/m.K (tested foil to foil)

What if my void width is greater than 400mm?

We can manufacture bespoke sizes of TW Cavity Barrier and Firestop to protect voids up to 1,200mm. Please contact our technical services team with your project details for more information

Case Studies

Related projects

Siderise is a market leader in the design and development of specialist passive fire.

View all
Contact us

We're here to help you

Talk to us

Call for our main switchboard

+44 (0) 1656 730 833

Ask technical

Email us for technical enquiries

technical.services@siderise.com

Ask site services

Email us for site support

site.services@siderise.com

Complete a form

Complete the form for the right response

Contact us