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Rigid polyisocyanurate foam insulation boards to BS 13166; available with mineral tissue (SarnaTherm G) or foil facing (SarnaTherm S). Also available in uniform thickness (SarnaTherm G / SarnaTherm S) or tapered (SarnaTherm G Tapered / S Tapered).


SarnaTherm G and S can be attached to the substrate (deck or suitable vapour control layer) by mechanically fastening with SBT tubes and SBIW-70x70 pressure plates, or for SarnaTherm G only by bonding in Sarnacol 2162 cold bonding adhesive or Sika C250 spray applied adhesive. SarnaTherm G & S can be loose laid if sufficient ballast weight is provided immediately, to resist wind uplift pressures.

A vapour control layer will generally be required when SarnaTherm G & S is used.

General information
Specification data - Polyisocyanurate (PIR) foam boards
Product Reference

SarnaTherm G

SarnaTherm G Tapered

SarnaTherm S

SarnaTherm S Tapered

Standard product features


  • Low thermal conductivity: 0.027 W/mK (thicknesses <80mm).
  • 0.026W/mK (thicknesses from 80mm to 120mm).
  • 0.025W/mK (thicknesses >120mm).
  • Class O fire rating to the Building Regulations.
  • <5% smoke emission when tested to BS 5111-1.
  • CFC/ HCFC-free.
  • Zero ODP (Ozone Depletion Potential).
  • Typical Density of 32kg/m³.
  • Compressive strength >150 kPa at 10% deformation.

Product Options

Product reference:

- SarnaTherm G:

  • Mineral tissue faced.
  • Factory Mutual approved for adhered applications, can be adhered, mechanically fastened or loose laid in warm ballasted or green roofing systems (refer to manufacturer for guidance).

- SarnaTherm S:

  • Foil faced
  • Factory Mutual approved for mechanically fastened applications, can be used in warm ballasted and green roofing systems.


Consult Sika Sarnafil for recommendations and details.

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