• Merlin Barrier Coat for use with Calcium Sulphate Screeds


    Merlin Barrier Coat for use with Calcium Sulphate Screeds

    Price is per one kit.

    Merlin Barrier Coat is a durable solvent free epoxcoating system specially formulated for use as a water resistant membrane in both new build and refurbishment projects. Barrier Coat can be applied directly onto wet surfaces free from standing water and when used as a primer and allowed to cure will accept most adhesives, coatings and screeds. Barrier Coat has been tested and certified to meet BS 476 surface spread of flame, Class 0 and has been assessed by the Building Research Establishment for water vapour permeability.


    In general usage, on a flat floor surface and under normal site conditions - one 5 kg kit will cover

    • approx. 25 m² - two coat application using a roller.
    • approx. 20 m² - using a squeegee

    Benefits of Merlin Barrier Coat

    • No harmful solvents

    • Penetrates into wet substrates

    • Fire retardant

    • Very high water vapour resistance

    • Excellent adhesion to wet concrete

    • Will tolerate lightly contaminated substrates

    Substrate Preparation

    Prior to the application of Barrier Coat, the surface must be clean, cured sufficiently to take foot traffic and be free of surface water or laitance. All surfaces must be sound, free from oil, grease and loose material. Mechanically prepare the area to give a suitable key for the Barrier Coat. Remove all debris by sweeping or vacuum. The air and surface temperature must be above the minimum required both during application and the curing process. The use of naked flame heaters is not advisable as they increase the relative humidity to a point which condensation can form on the cured Barrier Coat leading to reduced adhesion of any subsequent application.

    Technical Information Merlin Barrier Coat

    Mixing Ratio

    3:2 by weight

    Application rate

    1st coat 4 m_ per kilo

    2nd coat 6 m_ per kilo

    Porosity of the substrate can affect coverage

    Working life

    40 minutes @ 20° C

    Dry film thickness

    1st coat 225 microns

    2nd coat 150 microns

    Total 375 microns

    Minimum application temperature

    Maximum air RH Maximum slab RH

    8° C



    Cure time:

    Touch dry

    Foot traffic

    Over coat

    12 hours @ 20° C

    18 hours @ 20° C

    14 hours @ 20° C

    Lap shear adhesion: Adhesion to damp concrete (abraded):Adhesion to wet concrete (applied through surface water):

    16.0 Mpa

    10.0 Mpa

    4 Mpa


    84 Shore D

    Flash point

    Over 100° C

    Click for: Technical Datasheet Merlin Barrier Coat with Calcium Sulphate Screeds

    Click for: Technical Datasheet Merlin Barrier Coat 

    Click for:  Merlin Barrier Coat Base - Safety Datasheet

    Click for:  Merlin Barrier Coat Activator - Safety Datasheet

    Click for: NBS Specification Clause

    If you require further technical guidance for this product - please contact us on:

    Email:  info@smetbuildingproducts.com 

    Tel: 01 697 8586

    Tel: +44 (0)28 30266833