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Thermo-loc Platinum+ FX

Universal closers for eliminating damp and cold bridging around doors, windows, and sills.

Use cases:

  • To close the cavity at external doors, window jambs and sills
  • To provide thermal insulation and prevent ‘cold bridging’
  • To provide a DPC at external doors, window jambs or sills
  • Suitable for cavities up to 150mm

For more information call 01405 765567 Free next day delivery *

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Features & Benefits

  • Provides an effective DPC and thermal barrier between frame, inner and outer wall leaf
  • Thermal conductivity of 0.031W/mk
  • Exceeds the minimum thermal resistance path of 0.45m2 K/W stipulated in accredited construction details
  • Rigid profile extrusion allows first and second fix
  • Durable and resistant to decay
  • Simple on-site trimming to cope with ‘rogue’ cavity widths
  • Global warming potential of less than 5
  • Ozone depletion potential of zero
  • Available fully rebated - Check reveal (single flange)


Technical Information

  • BRE Document ‘Thermal insulation: avoiding risks’ stipulate “When a window or door frame is set back behind the inner face of a dense outer masonry leaf, it should overlap an insulated closer by a minimum of 30mm for BRE exposure zones Sheltered to Severe; but fully rebated (check reveals) for zones Very Severe”
  • With reference to insulation, the products in this range do not use, contain or produce Urea Formaldehyde, CFC’s or indeed any of the so called soft CFC’s, ie. HCFC’s & HFA’s. They have an ozone depletion potential of zero and global warming potential of less than 5 and complies with BS EN 13163.


  • Manufactured to BS EN ISO 9001 and BS EN ISO 14001
  • Complies with Building Regulation Approved Documents C, L1 & L2
  • Satisfies BRE document ‘Thermal insulation: avoiding risks’
  • Meets all relevant British Standards
  • Satisfies NHBC standards

Material and colour choice

  • Rigid profile extruded in UPVC
  • Platinum expanded Polystyrene insulation 0.031W/mk
  • Multi 100mm, Multi 100mm CR and fixed cavities
  • 2.4m lengths

How to order

  • Establish the cavity width and select the correct cavity closer width to ensure the cavity can be closed
  • In jamb and sill applications, first estimate the total length of cavity closer required, then order the correct number of individual 2.4 metre lengths so no joint pieces

Installation advice

  • The accredited construction detail published by DCLG require a minimum overlap of 30mm between the window frame and cavity closer
  • Cut the cavity closer into the required lengths allowing the jamb section to overlap the sill section by cutting away parts of the fixing flange and to butt the underside of the lintel
  • For second fix applications, the cavity closer is pushed into the open cavity after building work is complete. The compressible nature of the exposed insulation material is used to create a friction fit in the cavity, or alternatively the insulation can be trimmed to fit using a sharp knife
  • Fixing nails to the flanges are recommended to ensure a secure fit
  • Cavity insulation should butt tightly to the cavity closer

Bill of quantity

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

  • To extend not less than 150mm beyond ends of lintels/bridgings.
  • Manufacturer: Timloc Building Products, Ozone Park, Howden, East Yorks. DN14 7SD. T: 01405 765 567 W:
  • Reference: eg.FX2.4/50 (Thermo-loc Platinum+ FX, Expanded Polystyrene, 2.4m, 50mm)
  • nbs plus
  • riba

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