FOX PURMAX® 1K FS401 is a single-component, polyurethane-based, 400% elongation at break, impact-resistant, low-viscosity, cold-applied brush-grade waterproofing coating. It complies with the TS EN 1504-2 standard.

Colour Palette

Packaging

25 kg
TDS

Product Description

FOX PURMAX® 1K FS401 is a single-component, polyurethane-based, highly elastic waterproofing coating with 400% elongation at break. It is a cold-applied brush-grade waterproofing material with low viscosity and resistance to point impacts. It complies with the TS EN 1504-2 standard. It can be easily applied by roller, brush or airless spray. It provides excellent adhesion to concrete and maintains its performance over a wide service temperature range (-30°C / +80°C). It is suitable for use in interior and exterior areas, under-tile applications, terraces, balconies, roofs, tunnels, collection tanks and underground water tanks.

Key Benefits

  • Its single-component formula enables fast and practical application without the risk of mixing errors.
  • With 400% elongation at break, it provides long-lasting protection against structural cracks and movements.
  • As it can be applied by roller, brush or airless spray, it easily adapts to different surface geometries.
  • With adhesion strength of >2 N/mm² to concrete, it forms a reliable and permanent waterproofing layer.
  • Its service temperature range of -30°C / +80°C ensures effective performance in cold climates and on heat-exposed surfaces.
  • Its TS EN 1504-2 compliant structure allows confident use in concrete protection projects requiring technical specifications.

Advantages

  • Easy and fast application due to its single-component nature.
  • Can be applied by brush, roller or airless spray.
  • High elasticity and flexibility.
  • Excellent adhesion to concrete.
  • Excellent mechanical properties.
  • High adhesion strength.
  • Impermeable to liquids.
  • Excellent crack-bridging properties even at low temperatures.
  • Resistant to ponding water on terraces.
PropertyValue
Density (TS EN ISO 2811-1)1,43±0,05 gr/cm³
ColourGrey
Tensile Strength (ASTM D 412)>5,5 N/mm²
Adhesion Strength (ASTM D 903)>2 N/mm² to concrete
Viscosity (EN ISO 3219)2500-3500 cP
Water Vapour Permeability (ASTM E 96)0,8 gr/m² hour
ThinningNot thinnable
Shore A Hardness (TS EN ISO 868, 7 days)60
Elongation at Break (ASTM D 412)%400
Heat Resistance80°C – 100 days
QUV (ASTM G53)2000 hours
Application Temperature+5°C / +35°C
Service Temperature-30°C / +80°C
Pot Life40 minutes
Recoat Time8-24 hours
Full Cure Time7 days
Shelf Life6 months (from date of manufacture, stored at +5°C/+30°C)
Standard ComplianceTS EN 1504-2

Usage Areas

  • Interior and exterior areas (under-tile applications)
  • Terraces, balconies and all wet areas
  • Roofs and garden terraces
  • Planter box waterproofing
  • Positive-side waterproofing of foundations and retaining walls
  • Tunnels
  • Collection tanks
  • Ornamental ponds
  • Underground water tanks
  • Terraces above car parks

Application Steps

  1. 1

    Surface Preparation – Concrete

    Oil, grease, fuel and paraffin residues must be removed; the surface must be freed from release agents, cement residues, loose particles and cured membranes. Surface defects and corners must be repaired with FOX MORTAR FC188 T repair mortar to form a fillet of at least 4 cm radius. Surface cracks must be filled with FOX PURSEAL PS600 polyurethane mastic. Concrete surfaces must have a minimum compressive strength of 25 N/mm², a minimum tensile strength of 1.5 N/mm², a maximum moisture content of 4%, and the surface temperature must be a minimum of +5°C.

  2. 2

    Surface Preparation – Asphalt

    The asphalt surface must be cleaned with a water jet. For applications subject to vehicle traffic, the load-bearing capacity of the asphalt must be appropriate for the loads in use. The asphalt surface must be shot-blasted so that at least 60% of the aggregates are exposed.

  3. 3

    Priming

    The appropriate FOX EPOTHANE® series primer must be selected according to the surface type and applied to the surface to be coated. Ensure that the substrate temperature is a minimum of +5°C. Proceed with the application of FOX PURMAX® 1K FS401 within the overcoating time of the primer.

  4. 4

    Mixing

    As FOX PURMAX® 1K FS401 contains pigments and fillers, it must be thoroughly mixed with an electric mixer at 300–400 rpm and an epoxy/polyurethane resin mixing paddle until a homogeneous colour is achieved and no product remains on the bottom and sides of the container. Avoid over-mixing to minimise air entrainment.

  5. 5

    Waterproofing Application

    FOX PURMAX® 1K FS401 is applied by roller, brush or airless spray in a minimum of two coats. A waiting period of at least 8 hours and a maximum of 24 hours is required between coats. After the first coat application, a 60 gr/m² reinforcement mesh is applied; then the 2nd coat is applied. If used under a covering (ceramic, marble, etc.), the 2nd coat must be broadcast with 40–45 AFS silica sand while still wet.

  6. 6

    Cleaning of Tools and Equipment

    After application, tools and equipment used must be cleaned with solvent or polyurethane thinner. Once FOX PURMAX® 1K FS401 has cured, it can only be removed from the surface by mechanical means.

Critical

Concrete surfaces to be coated must be at least 3 weeks old prior to application.

Critical

After application is complete, the coating must be protected from direct water contact for at least 24 hours. If water contact occurs, softening and blistering will develop on the coating and its properties will be lost; in this case the coating must be completely removed and reapplied.

Critical

Application temperature must be a minimum of +5°C and a maximum of +35°C. Surface, ambient and material temperatures must be kept within this range.

Critical

Relative humidity must be a maximum of 80%. Attention must be paid to dew point and condensation. The substrate temperature must be at least +3°C above the dew point.

Critical

Mixing must be carried out with an electric mixer at 300–400 rpm and an epoxy/polyurethane resin mixing paddle. If the specified mixing paddle is not used, air will be entrained into the product and air bubbles will form on the coating.

Important

Surfaces to be coated must be pre-primed with a suitable FOX EPOTHANE® series primer.

Important

If used under a covering (ceramic, marble, etc.), the 2nd coat must be broadcast with 40–45 AFS silica sand while still wet.

Important

Materials to be used in cold weather must be brought to the application site 1–2 days in advance and kept at +20°C – +25°C to acclimatise to ambient conditions.

Important

Rain, dust, wind, animals and insects must be prevented from entering the area while the coating is still fresh.

Important

The product must be stored between +5°C and +30°C, away from direct sunlight, in a cool and dry environment. Shelf life is 6 months from the date of manufacture.

Critical

Open flames near storage and application areas are dangerous; areas must be ventilated. Work clothing, protective gloves, goggles and a mask must be worn during application. In case of contact with skin or eyes, wash thoroughly with plenty of water and soap; if swallowed, seek medical attention immediately.

Information

Consumption figures are given for ideal conditions assuming an ambient and surface temperature of 20°C. Consumption may increase on uneven surfaces and in cold weather conditions.

Information

Technical property values are given for +23°C and 50% relative humidity conditions. Higher temperatures shorten the time; lower temperatures extend it.