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.
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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.
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
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
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
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
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
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
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.
Concrete surfaces to be coated must be at least 3 weeks old prior to application.
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.
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.
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.
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.
Surfaces to be coated must be pre-primed with a suitable FOX EPOTHANE® series primer.
If used under a covering (ceramic, marble, etc.), the 2nd coat must be broadcast with 40–45 AFS silica sand while still wet.
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.
Rain, dust, wind, animals and insects must be prevented from entering the area while the coating is still fresh.
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.
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.
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.
Technical property values are given for +23°C and 50% relative humidity conditions. Higher temperatures shorten the time; lower temperatures extend it.
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