Unrivalled fire resistance performance meets highest engineering strength to create the Number 1 Off Site Manufacturing building board.

Superior Attributes
  • BBA certified
  • Euroclass A1 non-combustible to EN 13501-1
  • Extra strength
  • Moisture resistant
  • Impact resistant
  • Score & snap cutting
  • Easy fixing method
  • Environmentally friendly
Key Applications
  • Load bearing & non-load bearing fire resistant wall partitions
  • Fire resistant new-build & retrofit ceilings and floors
  • Timber frame & SIPs fire mitigation sheathing board
  • OSM, pods & park home manufacture
  • Prisons, anti-vandal units & high traffic locations prone to abuse
  • Carrier board for external brick slips
  • Stove surrounds (12mm board)

Multi-proXS is the Xtra Strength magnesium oxide board (MgO) with extra embedded layers of highest grade reinforcing mesh developed to offer Category 1 racking strength with sector leading fire resistance performance.

Multi-Pro XS is naturally cured using little to no energy through cold fusion, unlike similar competitive products which use autoclaving technology. This ensures that Multi-Pro XS has a relatively low impact on the environment, whilst achieving superior strength and flexibility through the introduction of four layers of alkaline resistant glass fibre mesh. Our consistent high quality is maintained and monitored through a sophisticated digitally controlled process to ensure a superior finish that always meets our committed quality assurance.

A firm favourite in manufacturing facilities across the UK & Ireland Multi-proXS handles, cuts and fixes with no fear of edge damage or breakout even when gun nailed within 9mm of board edge. It offers the complete solution for applications plywood, OSB3 and gypsum based boards can’t handle.

Whether in the factory, on the construction site or within the finished building, Multi-proXS always delivers on performance due to its exceptional properties.

Density1050 kg/m3
Reaction to FireEuroclass A1 to EN13501-1
Thermal Conductivity0.307 W/mK
Dimensional Tolerance Length & width+/- 2mm
Dimensional Tolerance Thickness+/- 0.2mm
Dimensional Tolerance Edge Straightness1mm per metre
ThicknessLengthWidthWeight per Sheet
  • Can Resistant boards be used externally?

    Yes, they can be used externally however they are not designed to provide a permanent exterior finish. They will stay looking good and last long when correctly specified, fitted and finished in semi-exposed external applications. Resistant boards are commonly used for semi-exposed external applications such as soffit boards (more durable than plywood), underside of canopies, porches, carports, balconies, carpark ceilings, agricultural ceilings, underpasses, stairwells etc. For the most demanding external applications Multi-rend & Multi-proXS provide the highest performance.
  • What fixings do I use?

    For internal use - any standard self-tapping countersunk screws are feasible. These should be readily available from all local merchants. On a full 8’ x 4’ sheet when fixed at 300mm centres vertically and at 600mm centres you will need 27 fixings per sheet. For Service Class 2 conditions within a building cavity – minimum 12 micron zinc electro galvanised gun nail or stainless steel.
  • Resistant Building Products Fire Resistance Testing – Multi-proXS

    Resistant have carried out numerous UKAS Fire Resistance tests on various partition assemblies designed to prove 60, 90 & 120 minute performance. A summary of UKAS Fire Resistance tests carried out can be accessed by downloading ‘Resistant Wall Test Makeups’. Full test reports can be provided on request. Resistant have also carried out fire resistance testing using Multi-proXS to the exacting standards of the Structural Timber Association (STA) to prove compliance with their industry guidance produced in association with the HSE “Design Guide to Separating Distances During Construction”.
  • Which Resistant products are racking boards?

    Resistant 6.5mm & 9mm Multi-proXS have been specifically developed to conform to racking requirements. Resistant 9mm Multi-proXS is UKAS tested and proven to fully exceed the minimum Category 1 Racking resistance strength required when fixed at standard 150mm perimeter fixing centres (full reports available on request). Resistant 6.5mm Multi-proXS is UKAS tested and proven to meet the minimum requirements of Category 1 Racking resistance when fixed at the closer 100mm perimeter fixing centres (full reports available on request).
  • What is racking strength?

    The Structural Timber Association details that vertical diaphragms or shear walls are commonly described as racking panels or walls in timber frame construction. They resist horizontal actions and are essential elements in the overall stability of the construction. A racking wall gains its strength from a wood-based board sheathing material or plasterboard lining material fixed to the walls studs which provide racking stability and sliding resistance by its connection to the horizontal diaphragms and foundations. The general construction and offsite manufacturing industry are mainly interested in boards which exceed Category 1 racking strength.
  • Do all Resistant boards share the same strength properties?

    The boards do not share the same strength properties. Although material composition is very similar, the actual strength is determined by thickness, density and number of layers of alkaline resistant, glass fibre reinforcing mesh within each board. Multi-proXS is an extra strength board which has 4 layers of reinforcing mesh to provide engineering racking strength.
  • What boards are recommended for use behind a wood burning stove?

    All 12mm boards across the Resistant range are suitable for use behind a wood burning stove however 12mm Multi-Pro XS or 12mm Multi-rend would be suitable for the most demanding applications as these are the highest performing boards. Please see the ‘Solid Fuel Stove Brochure’ available for download.
  • Can 9 or 12mm Resistant Multi-Pro be used in place of plasterboard?

    Yes. Our boards have far superior properties in comparison with plasterboard such as fire resistance, impact strength, breathability performance and durability to damp.
  • Can Resistant boards be painted and plastered?

    Before applying paint or plaster the board requires priming on face and edges with an acrylic-based primer. Please refer to the ‘Primer Information Page’ available for download which details various primers which have been tested for use with the board.
  • Do Resistant boards need to be hard fixed or can they be dot and dabbed?

    Resistant Building Products always recommend mechanically fixing the boards. In-house testing has been carried out using CT1 Grip & Grab adhesive, by fixing our boards back to timber and block, a suitable adhesion was achieved where the adhesive would only be suitable to offer a temporary fix. The adhesive could be used together with screws and nails for an extra strength fix. (Please see our ‘Accessories Information Page’ for more detail). Detailed mechanical fixing guides for all Resistant products are available for download.
  • How are the boards cut?

    Very easily! By score and snap with a standard craft knife, Stanley blade and can be hand or machine sawn. We would recommend a saw with Tungsten Tipped Carbide blade. A video of the score & snap method can be found here.
  • Do we have a pull-out test for screws?

    A series of our boards have been tested for pull-out strengths with Ejot, Sympafix and Rawlplug fasteners to name a few. These reports are available upon request.

Composite Panel Information Sheet


Passive Fire Brochure


BBA Certificate


Multi-Pro XS Technical Data


Multi-Pro XS Fixing Guide


F&B MultiProXS


Case Studies (5)

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