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JOINTFLEX® Closed Cell Polyethylene Fillerboard


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Product Description

CORKJOINT JOINTFLEX® Closed Cell Polyethylene Fillerboard is a closed cell, crossed linked, non-absorbent polyethylene expansion joint fillerboard for use in expansion and isolation joints in concrete and masonry structures. Jointflex® is non-absorbent and has excellent properties allowing it to be used in water retaining and excluding structures where potable, salt, chlorine and sewerage water is present.

Jointflex® has no bitumen content and joint sealant can be directly applied on top of it without the use of a bond-breaker tape. Jointflex® is available in standard 50kg/m³ (low) density and is also available in custom densities of 100kg/m³ (medium) and 150kg/m³ (high).

Supplied in sheet form and at a thickness to suit the joint width or can be custom cut in sheet sizes to suit the concrete thickness or width. Also available upon request with a tear-off cap to suit the joint sealant application depth.


  • Non-absorbent.
  • Lightweight & durable.No bitumen content.
  • Ability to compress and recover.
  • Non-extruding from joint movement.
  • Suitable for submerged or trafficable joints.
  • For use with polyurethane, polysulphide, silicone, acrylic and bitumen joint sealants.

Tested and conforms to ASTM D1752-18 & ASTM D545-19 standard specification for preformed expansion joint fillerboard paving and structural construction.

Areas of Application

  • Slab on ground
  • Brickwork and blockwork
  • Reinforced concrete structures
  • Concrete roads and pavements
  • Basements and tunnels
  • Water retaining / excluding structures
  • Dams and reservoirs
  • Bridges and viaducts
  • Suspended slabs Airport aprons and taxiways

Note : The product’s design and performance, its intended use, installation and final confirmation and approval for use, must be provided by the project’s Design Engineer and Project Manager.

    Available Sizes

    • Standard sheet size 2m (L) x 1m (W)
    • Density : 50kg/m³ (low density)
    • In thicknesses of 10, 12, 15, 20 and 25mm.
    • Custom thickness above 25mm are also available
    • Custom sheet sizes and thicknesses available to suit
    • Available with a tear off cap for easy joint sealant installation
    • Also available in 100kg/m³ (medium density) and 150kg/m³ (high density). Refer to CORKJOINT for further information.

    Physical Properties

    FOR 50kg/m3 DENSITY


    Note: The above physical properties are test results from an indepedent laboratory test report and a copy is available upon request. Material properties can vary between batches of ± 10%.

    Typical Applications


    Typical Installations

    Jointflex® is cut to size from sheets with a sharp retractable blade and adhered to the first concrete structure by a contact adhesive. Adhesive is applied directly to the Jointflex® in 50mm diameter ‘spots’ @ 300mm centers (approximately) or as required. Also refer to our installation method, available upon request

    Written Specification

    Where shown in the Brochure drawings, the expansion joint fillerboard shall be Jointflex®, closed cell, cross-linked non-absorbent polyethylene expansion joint fillerboard, with a minimum density of 50kg/m³, as supplied by CORKJOINT. The application / installation of the product must be in accordance with the manufacturer’s recommendations.

    Health and Safety Information

    For further information or advice on health and safety precautions, safe handling, storage and correct disposal of products, please refer to the most recent product Safety Data Sheet (SDS), which is available upon request


    The information and the recommendations relating to the application and end use of this product are given in good faith and are based on the information provided by the manufacturer of the product and/or the Company’s current knowledge and experience in connection with the product when properly stored, handled and applied under normal conditions and no liability of final function at the job site is assumed. In practice, the differences in materials, substrates and actual site conditions are such that no warranty in respect of merchantability of, or fitness for, particular purpose, nor any liability arising out of any legal relationship whatsoever, can be inferred either from this information, or from any written and/or oral recommendations, or from any other advice offered by the Company. The Company also has no express or implied knowledge of any particular purpose for which the product is required and any such information given will not be taken into account in the supply of this product. No responsibility or liability by the Company will be accepted for misuse, misreading or derivation from recommended guidelines in respect of this product and the user shall determine the suitability of the product for his intended use and assume all risks and liability in connection therewith. The information contained in our brochure may change at any time without notice. Any use of this product,  Jointflex®, in any application should be approved as suitable for use/application by the Design Engineer and Project Manager.