webertherm XM EPS PM320

Saint-Gobain Weber

Render protected, mechanically fixed external wall insulation (EWI) system based on expanded polystyrene (EPS) insulant, a weberend PTC second coat and a weber mineral TF top coat.

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Suitable for use in buildings with a floor not exceeding 18 m above ground level for England and Wales, with a reduced height of 11 m for Scotland.


Render protected, mechanically fixed external wall insulation (EWI) system based on expanded polystyrene (EPS) insulant with meshcloth reinforced basecoat, a top coat and a textured mineral finish.

Features and benefits:

  • Chlorofluorocarbon (CFC)/ hydrochlorofluorocarbon (HCFC) free.
  • Good impact resistance.
  • Provides weather protection.
  • Lightweight.
  • A wide range of finish coat colours are available.
  • Can be used for decorating and re-modelling existing facades.


Suitable for use in buildings with a floor not exceeding 18 m above ground level for England and Wales, with a reduced height of 11 m for Scotland.

System components:

  • Weber fixings as specified for the substrate.
  • webertherm EPS insulation (of specified thickness).
  • weberend LAC (first layer, 3 mm).
  • weber standard meshcloth.
  • weberend LAC (second layer, 3 mm).
  • weberend PTC (6 mm thick).
  • weber PR310 primer.
  • weber mineral TF.

The installation must be capable of resisting all dead loads and design live loads, including impact and wind loads, and accommodate all thermal movements without damage.

System installation is to be strictly in accordance with Saint-Gobain Weber specification. Please note that any other manufacturer's products used within the system will invalidate the guarantee, and the performance cannot be supported.

Remedial work must be completed prior to the installation of Weber EWI Systems.


  • The system should meet the building regulations requirements in compliance with BR 135. This includes achieving fire compartmentation of the structure using non-combustible fire barriers (webertherm MFL), installed vertically or horizontally at vulnerable areas such as window openings, doorways, penetrations and each floor level above the first floor level. The BR 135 recommends for each barrier to consist of a non-combustible material 100 mm minimum in height, which is fully bonded with weberend LAC and mechanically fixed using appropriate fire fixings through the meshcloth coat at maximum 400 mm centres. Additionally, install appropriate fire fixings (stainless steel as per BRE 135) at a rate of 1/m² minimum across the whole area receiving the above system.
  • Fixings must penetrate the structure in accordance with the fixing design to provide the appropriate pull out resistance. A survey of the building must be completed by an engineer to ensure the additional load does not have a detrimental effect on the building and the fixings are able to sufficiently penetrate the structure, to adequately support the Weber system. Weber will undertake fixing pull out tests and verify the adequacy of the fixing design based on a wind loading assessment carried out in accordance with BS EN 1991-1-4: 2005.

General information

Uniclass 2015

Ss_25_45_72_02 Adhesive-fixed external wall insulation systemsPrimary


M21/20 External wall insulation system

M21/210 External wall insulation system

Specification data - Adhesive-fixed external wall insulation systems

Product Reference

webertherm EPS PM320

For new, sound brick/ block or existing rendered/ un-rendered sound masonry substrates.

webertherm EPS PM320P

For heavy duty fibre cement sheathing or suitable alternative recommended boards/ panels.

Building height

Up to 18 m (maximum) for England and Wales. Up to 11 m (maximum) for Scotland. Insert requirement.


Not required

Weber CL150 Fungicidal Masonry Wash

Consult manufacturer for details.




webertherm EPS Expanded Polystyrene

EPS 70 E to BS EN 13163.


Dependent on required thermal transmittance (U-Value). Consult manufacturer and insert requirement.


To be confirmed on-site by pull out tests in accordance with BS EN 1991-1-4

Recycled content

Consult manufacturer for details and insert requirements.

Glass fibre reinforcement

webermesh standard

Balanced, open weave glass fibre meshcloth, coated for alkaline resistance. 1 x 50 m roll.


Required to comply with SWIGA guarantee requirements on all buildings greater than four floors in height above ground level. Consult manufacturer and insert requirements.

Cavity barriers

Type, thickness, density and compressive strength to be determined by the design team

Consult manufacturer for details.

Sealant joints

Low modulus silicone

Consult manufacturer for details.



First coat

weberend LAC

Standard. Uncoloured, polymer modified render, comprising FS2 sand, lime, cement, fillers and dry polymer.

weberend LAC rapid

To increase the speed of installation; consult manufacturer for details.

Second coat

weberend PTC

Polymer-modified, through-coloured, cement-based mortar for use as a render top coat, comprising FS1 sand, lime, powdered waterproofer, pigment, cement and dry polymer.

Finishing coat



weber PR310

Low viscosity liquid.


weber mineral TF

Cementitious factory batched textured finish.


Consult manufacturer's colour chart and insert requirements.


13.5 mm (minimum). Consult manufacturer and insert requirements.

Accessories/ Other requirements

See 'Options' and insert requirements.

Standard product features

Fire performance (to BS 476: Part 6 and 7):

Building Regulations National Class 0.


  • webertherm EPS: 0.72 m² per board.
  • weberend LAC: 6.5 kg/m².
  • webermesh standard: 45 m² per roll.
  • weberend PTC: 10 kg/m².
  • weber PR310: 0.25 L/m².
  • weber mineral TF: 2.25 kg/m².

Product Options


- Weber CL150 Fungicidal Masonry Wash:

For existing substrates, or where required on new substrates, drench apply CL150 wash and leave for 48 hours, then brush down to remove all moss/ growth.


  • Plain expanded polystyrene, SD/FRA grade.
  • Size: 1200 x 600 mm.
  • Nominal density: 14–16 kg/m³.
  • Thermal conductivity: 0.032 W/m·K.
  • Fire classification: Euro Class E; when part of webertherm XM: Building Regulations National Class 0 when tested to BS 476 Part 6 and 7.
  • Maximum water vapour permeability: 0.018–0.036 mg (P.a.h.m).
  • Fixings: Five required per insulation board.


- First coat:

To be applied in two coats, incorporating meshcloth insulation board. Apply 2–3 mm thick, incorporating weber meshcloth. Allow for partial take-up then apply further 3 mm to form a nominal 6 mm thick monolithic coat.

- Second coat:

For dry dashing or smooth floating to take synthetic finishes, coloured and polymer modified.

- Final coat:

  • Can be applied with a thin plastic float.
  • Primer: Can be brush, spray, or roller applied.

Accessories/ Other requirements:

Full system and render only beads, if required by the system or product, or if specified, shall be of appropriate design, gauge and material (aluminium/ polyvinyl chloride (PVC)/ stainless steel) - consult manufacturer for details. Some available accessories are listed below:

  • Clip on nose beads.
  • Compressible sealing tape.
  • Fire barriers: Consult manufacturer for details.
  • Full system Weber base bead: Aluminium box profile with clip on nosing.
  • Overcills.
  • Render-only drip/ corner beads.
  • Undercills.
  • Verge flashing.
  • Weber frame seal – Can be used as an alternative at windows to provide a mastic free seal with improved aesthetics/ maintenance.
  • Weber pre-coated, pressed aluminium under cill trims: 1.2 mm thick (nominal), size to suit EWI System, if required.
  • Weber pre-coated, pressed aluminium verge trims: 1.2 mm thick (nominal), size to suit EWI System, if required.
  • Weber PVC corner, stop, drip and movement beads: As required.
  • Z flashing.

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