Thermo-loc Platinum+ Cavity Closer

Cavity closers designed to eliminate damp and cold bridging around doors, windows, and sills.

Suitable for between 50mm-150mm cavity sizes. Single profile for 50mm-100mm cavities, double profile for 105mm-150mm cavities, Multi and Check Reveal Multi options also available. 25mm insulation thickness.

Compliant with Building Regulation Approved Documents C, L1 and L2 and satisfies BRE document ‘Thermal Insulation: avoiding risks’.


  • 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

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Product Information

Thermo-loc Platinum +

DescriptionCavity WidthLengthPack QuantityLead TimeProduct Code
Thermo-loc Platinum +50mm2.4m10Next Working DayPP2.4/50
Thermo-loc Platinum +75mm2.4m10Next Working DayPP2.4/75
Thermo-loc Platinum +90mm2.4m10Next Working DayPP2.4/90
Thermo-loc Platinum +100mm2.4m10Next Working DayPP2.4/100
Thermo-loc Platinum + Multi50-100mm2.4m10Next Working DayPP2.4/100MULTI
Thermo-loc Platinum +120mm2.4m107-10 working daysPP2.4/120
Thermo-loc Platinum +125mm2.4m10Next Working DayPP2.4/125
Thermo-loc Platinum +130mm2.4m107-10 working daysPP2.4/130
Thermo-loc Platinum +150mm2.4m10Next Working DayPP2.4/150
Thermo-loc Platinum + CR Multi50-100mm2.4m107-10 working daysPP2.4/CR100MULTI

  • Effective DPC and thermal barrier between frame, inner and outer wall leaf
  • Thermal conductivity of 0.031W/m²k
  • Exceeds the minimum thermal resistance path of 0.45m2 K/W stipulated in accredited construction details
  • Rigid profile extrusion allows 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)
  • 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
  • Rigid profile extruded in UPVC. Platinum expanded Polystyrene insulation 0.031W/mk. Multi 100mm, Multi 100mm CR and fixed cavities. 2.4m lengths.
  • The accredited construction detail published by DCLG require a minimum overlap of 30mm between the window frame and cavity closer.
  • Cut into required lengths allowing 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.
  • Establish the cavity width and select the correct cavity closer width to ensure the cavity can be closed.
  • In jamb and sill applications, estimate the total length of cavity closer required and order the correct number of 2.4 metre lengths ensuring no joint pieces.

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

  • 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.PP2.4/50 (Thermo-loc Platinum+, Expanded Polystyrene, 2.4m, 50mm)
  • 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, CFCs or indeed any of the so-called soft CFCs, ie. HCFCs & HFAs. They have an ozone depletion potential of zero and global warming potential of less than 5 and complies with BS EN 13163.

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