SIDERISE TW-P Firestops for Profiled Decks (formerly Lamatherm TW-PP and Lamatherm TW-PS)

Fire stop solution to seal the junction between the tops of compartment walls and the underside of profiled decking. Fire and smoke stop blocks are factory produced trapezoidal blocks which are shaped to close tolerances directly from a base mineral wool slab. The product provides a simple resilient 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.

TW-PS is a Class A1 rated foil-faced version of the product. 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.

TW-PP achieves a fire rating of up to EI 120 minutes to BS 476-20, TW-PS achieves a fire rating of up to EI 300 minutes to BS 476-20.

General information


TW-PP: Low resin mineral fibre

TW-PS: Mineral fibre core faced with Class A1 reinforced aluminium foil

Uniclass 2015

Pr_25_80_81_51 Mineral wool fire-stoppingPrimary


F30/670 Head of non-loadbearing walls

G30/240 Fire resisting profile fillers

P12/360 Mineral wool rigid batts

P12/40 Mineral wool rigid batts

Specification data - Mineral wool fire-stopping

Product Reference


60 minutes' fire rating, 75 mm length.


120 minutes' fire rating, 150 mm length.


30 minutes' fire rating, 75 mm length.


60 minutes' fire rating, 90 mm length.


120 minutes' fire rating, 120 mm length.


300 minutes' fire rating, 175 mm length.

Standard product features


  • TW-PP: Low resin mineral fibre.
  • TW-PS: Mineral fibre core faced with Class A1 reinforced aluminium foil.

Void bridging capabilities:

  • TW-PP: 30–400 mm.
  • TW-PS: Tops of walls: 200–1150 mm; Within ceiling void: 50–1150 mm.

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