Sika Sikafloor 400N Elastic

1-part, UV resistant, highly elastic, moisture-curing polyurethane waterproof membrane for pedestrian traffic

$35-$46 (light pedestrian), $57-$78 (medium-heavy pedestrian)

Coverage: 1 litre/m² (light pedestrian), 1.68 litres/m² (medium-heavy pedestrian)

Sikafloor-400 N Elastic is a 1-part, UV resistant, highly elastic, moisture curing polyurethane waterproof membrane.
  • Overview


  • Description


    Sikafloor-400N Elastic is suitable for applications to most common building substrates including concrete, fibre cement, plasterboard, timber, and some metals.

    It is suitable for use as a waterproof membrane for wet areas as described in AS 4858:2004 “Wet Area Membranes”.

    It can be used as a waterproof membrane and coating for:

    • Exposed roofs, decks, terraces, gutters, flashings, walls
    • Tanks, reservoirs and pipes
    • Shower recesses
    • Wet areas
    • Balconies
    • Retaining walls
    • Planter boxes
    • Slab floors


    • UV resistant and non-yellowing.
    • Excellent mechanical resistance.
    • Can be made slip resistant.
    • Versatile – can be used for a flexible coating and as a waterproof membrane.
    • Good crack bridging ability.
    • Excellent thermal resistance.
    • Fast curing
    • Good resistance to a wide range of chemicals and detergents
    • Approved in accordance with AS 3740 - 2010 “Waterproofing of domestic wet areas”.
    • Approved in accordance with AS 4020 - 2002 “Approval for Use in Potable Water”.


    On substrates with moisture content greater than 4%, a minimum 2mm thick Sikafloor-81 EpoCem or Sikagard-720 EpoCem temporary moisture barrier is required.

    Avoid applying Sikafloor-400N when rain is present or imminent.

    Do not apply Sikafloor-400N to wet or damp substrates

  • Performance


  • Compliances and Accreditations


    • AS 4020
    • AS 4858
  • Systems & Installation



    Surface Preparation

    Surfaces must be clean and free from all traces of loose materials, old coatings, curing membranes, release agents, laitance, oil and greases etc. Substrate compressive strength should be at least 25MPa, pull off strength at least 1.5MPa.

    Structurally unsound layers and surface contaminants must be mechanically removed by abrasive blast tracking or grinding. Substrates heavily impregnated with oil must be cleaned by torching or suitable solvent cleaning methods. To check that all traces of oil have been completely removed,

    sprinkle a few drops of water over the surface. If all the water is quickly absorbed, the surface is sufficiently oil and grease free. If the water forms into globules that remain on the surface, further thorough treatment of the concrete is necessary.

    Sikafloor-400 N Elastic acts as a self-levelling coating and will not re-profile irregular substrates. For re-profiling defects on horizontal surfaces a suitable patching mortar is required. The patching mortar can be of epoxy or cementitious base depending on the scope, particular conditions and requirements of the work. Contact the Sika technical department for further information.


    For areas subjected to light wear, prime the substrate with one coat of Sikafloor-400 N Elastic diluted with 10% Sika Thinner C.

    Apply Sikafloor-160 as a primer for areas subjected to medium or high wear. Apply the primer in accordance with the technical data sheet.


    Stir thoroughly with an electric stirrer prior to use for 2 to 3 minutes at a low speed (300 – 450 rpm) until completely blended.


    Apply to the floor in an even layer, using a brush, roller (preferably solvent resistant), airless spray or notched trowel.

    Application Conditions

    Substrate temperatures
    Minimum +10°C (but min. 3°C above dew point) Maximum +30°C
    Relative humidity max. 80%


    If Sikafloor-400N Elastic is to be tiled, quartz sand should be broadcast into the topcoat to give the surface a mechanical key.

    Before tiling the membrane should be fully cured, tiling should commence immediately after it is fully cured. The membrane must be clean and free of dirt, oil, grease and contaminants. Tiling should be conducted using 2 part polymer modified tile adhesives and proper tiling practice should be observed.


    Clean all tools and equipment immediately after use with Sika Colma Cleaner. Once hardened, the material can only be removed mechanically. If in contact with hand and skin, thoroughly wash in hot, soapy water.

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  • Spec Clause

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    Sika Sikafloor 400N Elastic

    1-part, UV resistant, highly elastic, moisture-curing polyurethane waterproof membrane for pedestrian traffic

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