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Multiboard (External)

Multiboard (External)

Marmox (UK) Ltd Third party certifications:
  • BBA Agrément Certificate

    BBA Agrément Certificate

    Certificate type

  • QA Certificate

    QA Certificate

    Certificate type

Tile backer board for external use.

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+44 (0)1634 835290 www.marmox.co.uk


Suitable for use insulating, waterproofing and fixing ceramic and stone tiling and brick slips to external walls.


Waterproof, thermally insulating tile backer board for external use providing an effective decoupling layer between the tiled surface and the substructure. This helps to prevent tiles and grout from cracking due to horizontal movement in the floor and allows heavy weights to be safely and securely fixed to walls.

An internal board is available, specified separately.

Features and benefits:

  • Lightweight.
  • Dimensionally and structurally stable in all weather conditions.
  • Resistant to freeze-thaw damage.
  • Impermeable to water, and acts as a moisture barrier.
  • Thermal insulation is unaffected by various temperatures.
  • The cementitious surface is resistant to heat and chemicals.
  • Can easily be cut in straight lines.
  • Provides enhanced tile adhesion.
  • Load bearing capacity exceeds 100 kg/m².
  • Boards can be aligned horizontally or vertically.
  • Does not contain any hazardous substances.
  • Manufactured in accordance with ISO 9001 Quality Management Systems and BS EN 5385-2, and CE marked to EN 13164.

Boards should be stored flat and covered with scrim/ reinforcing tape. For fitting instructions onto different types of substrate, consult manufacturer's literature.

General information


Extruded polystyrene (XPS)


1250 x 600 mm

2500 x 600 mm

Uniclass 2015

Pr_25_71_63_29 Extruded polystyrene (XPS) boardsPrimary


M40/27 Intermediate substrate

M40/470 Intermediate substrate

Specification data - Extruded polystyrene (XPS) boards Enhanced data


To BS EN 13164.

Third party product certification

BBA Certificate: 09/4687.

Fire performance

Euroclass E.

Compressive strength (minimum) at 10% compression

>400 kPa.

Thermal conductivity (maximum)

0.034 W/m·K.


12.5 mm.

Thermal resistance (R-Value): 0.35 m²K/W. Board weight: 2.8 kg.

20 mm.

Thermal resistance (R-Value): 0.56 m²K/W. Board weight: 3.1 kg.

30 mm.

Thermal resistance (R-Value): 0.83 m²K/W. Board weight: 3.4 kg.

40 mm.

Thermal resistance (R-Value): 1.11 m²K/W. Board weight: 4 kg.

50 mm.

Thermal resistance (R-Value): 1.39 m²K/W. Board weight: 4.2 kg.

60 mm.

Thermal resistance (R-Value): 1.67 m²K/W. Board weight: 4.5 kg.

Face size (length x width)

1250 mm (±5 mm) x 600 mm (±2 mm).

2500 mm (±5 mm) x 600 mm (±2 mm).

Product Reference


External walls. For concrete block and brick substrates (flat). To be fixed with adhesive.


External walls. For aircrete block walls. To be fixed with adhesive or mechanically.


External walls. For rendered walls. To be fixed with adhesive or mechanically.


External walls. For intermediate plywood layers on timber/ metal frames. To be mechanically fixed.

Density (to DIN 53420)

36 kg/m³.

Water absorption (two day immersion, to EN 12087)

<1% by volume.

Water absorption (capillary, to DIN 53428)


Coefficient of linear expansion (to ASTM E-831)

0.07 mm/mK.

Water vapour diffusion factor (to EN 12086)


Ozone depleting potential (ODP)


Global warming potential (GWP)


Impact sound reduction (to BS EN 140-8)

21 dB.

Maximum tile loading weight

>100 kg/m² (dependent on adhesive and wall type).

Flexural strength (to ASTM C203)

>200 kPa.

Water vapour permeability (to EN 12086)

3.2 m.

Coefficient of linear expansion (to ASTM D-696)

30 x 10^-6 K^-1.


Marmox Tile backer boards and Shower bases

Marmox Tile backer boards and Shower bases

Third party certifications

  • Certificate: 09/4687
  • DoP (CE): Certificate: XPS-EN13164-T1-CS(10\Y)400-CC(2/1/10)115-WL(T)3

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