Merlin Barrier Coat (DPM)

Merlin Barrier Coat is a durable solvent-free surface DPM specially formulated for use as both a liquid damp proof membrane (DPM) or vapour control membrane for use in new build and refurbishment projects. Merlin Barrier Coat is a durable solvent-free epoxy coating 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.


Related Downloads

icon-pdf TDS Merlin Barrier Coat with Calcium Sulphate Screeds

icon-pdf TDS Merlin Barrier Coat_General Guidance_SMET

icon-pdf Merlin Barrier Coat Base _Safety Datasheet

icon-pdf Merlin Barrier Coat Activator – Safety Datasheet

icon-pdfSMET Floor Screed and Compounds Product Selector

NBSplus NBS Specification Clause for Merlin Barrier Coat

Benefits of Merlin Barrier Coat

• Very high water vapour resistance
• Excellent adhesion to wet concrete
• Will tolerate lightly contaminated substrates
• Can be safely used on calcium sulphate screeds
• Suitable for use with underfloor heating
• Can be applied to metal, timber, concrete, ceramic tiles, fibreglass, brick, and most existing coatings
• Penetrates into wet substrates
• Fire retardant
• Available in temperate and tropical grades

Areas of Use

• Damp proofing concrete and cementitious screeds (DPM)
• Vapour release control for Calcium Sulphate Screeds
• Sealing and priming cementitious surfaces
• Sealing and priming lightly contaminated substrates
• Surface DPM
• Can also be used in combination with other Merlin Coatings Systems

Technical Details for 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: 8° C
  • Maximum air RH: 100%
  • Maximum slab RH: 99%
Cure time:
  • Touch dry: 12 hours @ 20° C
  • Foot traffic: 18 hours @ 20° C
  • Over coat: 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
Hardness 84 Shore D
Flash Point Over 100° C


Case Studies using Merlin Barrier Coat

• Loughborough University*
• Dalham Hall Stud
• Sheffield Children’s Hospital*
• Ford UK
• Teeside Shopping Retail Park
• Thistle Oil Platform
• Kings High School for Girls
• Avery Mews Care Home*
• Eden Community School*
• Grandholm Care Home*
• Wakefield College*

*applied to calcium sulphate screeds

Packaging: Available in 5kg and 25kg units.