Technical Data | TW-P – Firestops for Profiled Decks | Construction | Products | Siderise

Siderise TW-P – Firestops for Profiled Decks – Technical Data

Version: 1.01 - Release Date: October 2021


Siderise TW fire stops for profiled decks comprise of a range of fire stopping solutions designed to seal the junction between the tops of compartment walls and the underside of profiled decking.
These bespoke products are made up of materials that are supplied in various configurations to cost-effectively suit the project requirement. In every case, the materials are tailormade to suit the shape and performance specification of the individual application.

Product Description

Siderise TW-PP fire stops are factory produced trapezoidal blocks which are shaped to close tolerances directly from a base mineral wool slab. The product provides a simple fire-rated seal to close cavities at the top of compartment walls in conjunction with profiled metal decking, coffered soffits and roofing etc. They are suitable for installation in any nominated cavity of fixed dimensions. 
Siderise TW-PP is available in set widths corresponding to the required fire rating. The major and minor dimensions are matched to the quoted internal dimensions of the profile. 
The material is cut to be nominally oversized in depth relative to the depth of the profile so as to ensure a tight compressive fit within the void.  
Should a smoke seal be required then the TW-PP must be coated with Siderise fire & acoustic gap sealant (or Siderise  TW-PS should be used). 
The Siderise  TW Fillet Blocks comprise of small section rectangular blocks of semi-rigid mineral fibre for a compressed installation within quoted metal decks. 
They are typically used to complement trapezoidal blocks as a double layer method of fire stopping holorib or dovetail deck profiles. 
The trapezoidal Siderise  TW-PP blocks are available to suit all metal decks and profiled cladding. Through a close working relationship with profile deck manufacturers, Siderise has built up an extensive database of profile types, facilitating specification and ordering. The profile reference or name of the deck can therefore be supplied at the point of enquiry to ensure the best solution for the project is selected. 
A Class A1 rated foil-faced version of the product is also available, referred to as Siderise TW-PS. This product comprises a specifically manufactured low resin content mineral fibre insulation core which is pre-compressed internally and shaped to close dimensions. The material is held in a robust lamella form by the application of reinforced foil to the exposed surfaces to give a Class A1 product. 
Please contact our technical team on for specific advice on product selection for your specific project requirements.

Fire Performance

The design and manufacture of Siderise TW is based on proven fire performance to BS 476: Part 20: 1987. 
Siderise TW-PP includes both 1 and 2 hours fire resistance in accordance with both insulation and integrity criteria. 
Siderise TW-PS includes fire resistance from 1 to 5 hours in accordance with both insulation and integrity criteria. 
The fire resistance in Table 1 applies to the sealing of gaps over walls constructed of lightweight aggregate concrete, dense aggregate concrete, concrete blocks or clay bricks which have a minimum density of 400kg/m
Verification of fire performance is available upon request.  
Non-standard widths are also available subject to enquiry on a project basis. Contact our technical team on for advice.

Table 1 - Fire performance

System Product code Fire rating (mins)  Block thickness (mm) 
TW-PP PP-FS60 60 75 
 PP-FS120 120 150 
TW-PS PS-CB30 30 75 
 PS-FS60 60 90 
 PS-FS120 120 120 
 PS-FS300 300 175 

Technical Specification

Siderise TW-P Firestops for profiled decks

Siderise TW-PP fire stops for profiled decks

Form supplied Low resin mineral fibre 50mm up to 120mm thick 
Colour Self coloured buff 
Finish Plain 
To suit profiles All 
Density Raw material 75 kg/m3 
Thermal conductivity λ = 0.04 W/m.K 
Acoustic performance Up to 44dB (Contact our Interiors technical team with project specific details for advice.) 
Reaction to Fire Class A1 to EN 13501-1 
Resistance to Fire 60 & 120 minutes (In accordance with BS 476); Please see Table 1 

Siderise TW-PS fire stops for profiled decks with aluminium foil facing

Form supplied Mineral fibre foil faced both sides 50mm up to 120mm thick 
Colour Silver 
Finish Aluminium foil 
To suit profiles All 
Density Nominal 75 kg/m3 
Thermal conductivity λ = 0.038 W/m.K (tested foil to foil) 
Acoustic performance Up to 51dB (Contact our Interiors technical team with project specific details for advice.) 
Reaction to Fire Class A1 to EN 13501-1 
Resistance to Fire 30 to 300 minutes (In accordance with BS 476); Please see Table 1 


Siderise Firestops for profiled decks are environmentally friendly:

  • They contain no Volatile Organic Compounds (VOCs) and no very Volatile Organic Compounds (vVOCs). 
  • Zero Ozone Depleting Potential 
  • Zero Global Warming Potential 
  • Recyclable

Additional Information

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: 

For Installation Training or Site Inspections please contact:


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.

SIDERISE GROUP Forge Industrial Estate, Maesteg, UK, CF34 0AY T: +44 (0)1656 730833 F: +44 (0)1656 812509 E: W:

Published Version: TW-P_v1_01_20211117_1725