External Wall Insulation Materials

ProRend EIFS can be installed using either expanded polystyrene (EPS), or mineral wool external wall insulation material. Both boast superb green properties:

  • CFC / HCFC free
  • Zero Ozone Depletion Potential (ODP) rated
  • Zero Global Warming Potential (GWP) rated

U Values And Dew Points

U values are a measure of the amount of heat conducted through an external wall insulation material per m2 at a given temperature. The lower the U value the less heat that will be lost through the walls.

A dew point is the temperature at which air becomes saturated: below this point moisture is deposited as condensation.

Properties constructed using external wall insulation are able to force the dew point to the outside of the wall.

The SAS technical team will provide you with a U-value and dew point calculation once you have provided us with the makeup of the wall.

Expanded Polystyrene, EPS

ProRend EIFS EPS external wall insulation material is manufactured to BS EN13163: 2001 is available in 3 grades:

  • • EPS 70 White – standard insulation with highest (poorest) thermal conductivity
  • EPS 70 Platinum – premium insulation with the best thermal conductivity of all insulants sold as part of the ProRend EIFS system. The use of Platinum EPS Insulation on a traditional cavity wall renovation could save you 20mm in thickness of insulation compared with EPS 70 White or Mineral Wool slab, saving on transport costs and sundry items such as fixings and beading profiles
  • EPS 200 White – dense insulation ideally suited to applications below DPC

Mineral Wool

ProRend EIFS Mineral Wool external wall insulation material is non-combustible and capable of withstanding temperatures of up to 1000°C. Mineral Wool is available in 2 grades:

  • Slab – best thermal conductivity of mineral wool insulants
  • Lamella – available in widest range of thicknesses and suitable for curved walls

Mineral Wool can be used as a sole insulant in ProRend EIFS projects or to serve as a fire barrier in EPS type application. Mineral Wool fire barriers are typically used as follows:

  • ProRend EIFS adhesive EPS applications using Mineral Wool Lamella
  • ProRend EIFS rail EPS applications using Mineral Wool Rail Slab

How much insulation do I require?

This varies on a case by case basis and is dependent upon which insulation is used. Contact our technical team and we can work with you to specify the right insulation for your project.

Mineral WoolEPS
Technical PropertiesSlabLamella70 White70 Platinum200 White
Thermal conductivity λ90/90 W/mK0.036*0.0400.0370.0300.033
Water vapour permeability,
μ(BS EN ISO 10456 2007 Table 4)
Fire classificationA1A1E †E †E †
Nominal density, kg/m3126 - 140126 - 14014 - 1614 - 1630 - 32

† Contains fire retarding additive
*Lambda may vary for 30-40mm

Insulation panel properties
Blunt edgeThickness, mm30 - 25030 - 30020 - *20 - *20 - *
Face, l x h, mm1200 x 6001000 x 2001000 x 5001000 x 5001000 x 500
Rail EdgeThickness, mm40 - 16040 - *40 - *40 - *
Face, l x h, mm500 x 500500 x 500500 x 500500 x 500
Tongue and grooveThickness, mm40 - *40 - *40 - *
Face, l x h, mm1050 x 5501050 x 5501050 x 550
Bends around curved walls

Note insulation panel thicknesses increase in 10mm increments.
Bespoke EPS shaped panels are available on request e.g. columns and decorative details.

SWIGA - Solid Wall Insulation Guarantee

SWIGA Guarantees are a 25 year insurance backed guarantees offering cover against defects in materials, workmanship and design.

The SWIGA guarantee is available as a separate guarantee to SAS (Europe) Ltd.’s own 10 year product guarantee and is supplied by SWIGA.


  • The work must be completed be a SWIGA contractor member
  • The contractor carrying out the work must be PAS2030 certified
  • The installed system must belong to a SWIGA system certificate holder member
  • The installed system must be BBA certified
  • The property must be 4 stories or less
  • A fee of £79 plus VAT must be paid to SWIGA by the property owner

Installers Obligations

  • Installers must be registered with SWIGA
  • Installers must be trained by the system manufacturer
  • Installers must be PAS2030 certified
  • A minimum of one PAS2030 certified installer must be on site for every four uncertified installers at all times
  • Installers must submit a pre-notification form to SWIGA at least 5 working days before the installation start date
  • Work cannot commence until the installers have received authorisation from SWIGA
  • Installers must submit the application for the guarantee once the work is completed and the installation has been signed off by the system manufacturer

SAS (Europe) Ltd's Obligations

  • SAS must train the installers to PAS2030
  • SAS must issue installers with ID cards
  • SAS must endorse the installers application to become SWIGA registered
  • SAS must carry out a minimum of two ‘work-in-progress’ site inspections per year for each installer
  • SAS must advise SWIGA of the names of trained individuals