Sikaflex® PRO-3 Purform® is ready for the needs of tomorrow, with Sika Purform® polyurethane technology inside. Sikaflex® PRO-3 Purform® technology gives superior mechanical properties together with good adhesion, outstanding weathering, and high chemical resistance, plus much more, to provide durable, high performance joint seals in floors and civil engineering structures. It was designed to have the right balance of properties for outstanding results in application, performance, and durability.

Click on the yellow bullet points in the puzzle below to learn about Sikaflex® PRO-3 Purform®

1. Purform Polyurethane Technology

Sika Purform® Technology builds on the strengths of polyurethane and gives our engineers the tools to create new Sikaflex® products with high performance and ultra-low, free monomer diisocyanate contents.

Sikaflex® PRO-3 Purform® is the state-of-the-art and next generation joint sealant for floors and civil engineering structures, with the right balance of properties for the best overall results, thanks to the features, advantages and benefits of the Purform® technology.

Sikaflex® PRO-3 Purform® is impressive with faster curing and increased durability, plus it is non-staining with increased substrate compatibility and very low monomeric diisocyanate.

Purform polyurethane technology

2. Applications

Sikaflex® PRO-3 Purform® is now the first choice for performance, quality, and durability. Typical structures and applications for horizontal joint sealing with Sikaflex® PRO-3 Purform® range from parking decks to sewer plants, as well as floors in warehouses, production and processing areas, even clean rooms due to its ultra-low emissions.

In addition to accommodating movement, these joints can be exposed to weathering, mechanical impact, and chemical exposure. Sikaflex® PRO-3 Purform® provides a unique balance of properties.

3. Application Properties

Sikaflex® PRO-3 Purform® has outstanding application characteristics, essential for productive work rates and finishing with good-looking joints. Professionals using Sikaflex® PRO-3 Purform® appreciate its:

  • Low application force, allowing easy and efficient application.
  • Non-sag properties, so the sealant stays where it is applied
  • Short cut-off strings, meaning less mess and no time is lost cleaning
  • Good body and tack-free surfaces, making it easy to tool and achieve a visually attractive surface finish
  • Low odor and ultra-low VOC’s, making it for safe application and use indoors

4. Mechanical Properties

The most durable and reliable joint sealing is not usually achieved by the product with the highest specific chemical resistance, UV resistance or movement capability. Generally, the best results are achieved by products that offer the best compromise for application, performance and durability!

Sikaflex® PRO-3 Purform® has a unique balance of properties that can provide the necessary movement accommodation with outstanding mechanical properties, weathering and chemical resistance, as well as good substrate compatibility and ultra-low emissions.

  • Movement capability: ± 50% (ASTM C 719) and class 25 HM (ISO11600)
  • Weathering resistance: 10 cycles (ISO 19862), no visible cracks after 5000 hrs. QUV
  • High tear resistance: 9 N/mm (ISO 34)
  • Outstanding compatibility: non-staining on many natural stones
  • High chemical resistance: Fuels and liquid chemicals (DIN EN 14178-6)
  • External certification from well-known testing authorities: EN15651-4, EN 14188-2, ASTM C920, etc.
  • Lowest impact: Ultra-low monomer content, future proof. Highest EHS certification EC1 Plus, A+, M1

5. Chemical Resistance

Floor joint sealants are exposed to chemicals. For example:

  • Spillage from vehicles such as fuels and oils
  • Cleaning and disinfecting products that are soapy, or strongly acidic or alkaline liquids, or even solvents.
  • Organic acids after many unknown chemical combinations in sewage treatment plants

Sikaflex® PRO-3 Purform® can handle all this!

There are several methods defined to determine the impact of chemicals on joint sealants, and the test method described in EN 14187-6 is regarded to give complete and realistic results to measure this. In testing, H-specimen samples (substrate-sealant-substrate) are submerged in the defined test liquids for a defined time and then elongated to 100%.

The samples must maintain function, remain elastic and not fail adhesively or cohesively. The joints are a system of substrate and sealant and therefore this system must be assessed together as a whole. The full picture from EN 14187-6 test results shows that Sikaflex® PRO-3 Purform® has excellent chemical resistance for many applications and areas of use.

6. Weathering Resistance

Joint sealants must safely accommodate the anticipated level of joint movement, whilst being cyclically exposed to weathering, with wind and rain, snow and ice, with high and low temperatures, plus UV light radiation from the sun, and any other specific aspects of the environment such a marine salts and industrial pollutants etc. All this has an impact on the durability of the sealant in service as it ages.

Joints sealed with Sikaflex® PRO-3 Purform® are very reliable and long-lasting based on the proven Sikaflex® polyurethane technology, now made even better with Purform® technology.

Sikaflex® polyurethane sealants stay permanently flexible and elastic and do not get hard, even after years in service. Other joint sealing technologies tend to continue to harden post-curing, eventually making them hard and less elastic, so prone to failure. Sikaflex® Purform® polyurethane is built from the new Purform® prepolymers, which means that this next generation Sikaflex® PRO-3 Purform® has superior performance and long-term stability even in hot and humid conditions.

At Sika we put big efforts in providing reliable and durable solutions and rigorously test our products. For example, we undertake long-term mechanical testing after storage in the most adverse conditions or cyclic elongation and compression together with UV irradiation and much more.

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7. Sustainability

At Sika reliable and long-lasting joint sealants represent sustainability in action, which Sikaflex® polyurethane products have now proven for many decades. The disruption, effort and costs to refurbish damage from water ingress through the joints is not sustainable.

For the health and safety of Sika’s customers, we strive to reduce the amount of any harmful chemicals in our products. Even when you consider that any such exposure during joint sealing works is only minimal, the use of Sikaflex Purform® polyurethane allows us to reduce this even further in these high performance products.

Sikaflex® PRO-3 Purform® meets the highest VOC standards (EC1 Plus, A+, M1), is solvent free and has free monomeric diisocyanates contents far below the REACH 2023 limits.

Less impact, more sustainability

8. Certificates

Certificate logo

Sikaflex® PRO-3 Purform® is predominantly used because it is specified on projects by architects, engineers and other designers and specifiers, who understand the performance and durability requirements of their clients. For these people it is the evidence that counts, meaning products with all necessary approvals and certification to the relevant standards, plus easy access to expert technical support and references, such as provided by Sika.

Sikaflex® PRO-3 Purform® has many certificates of approval and meets all relevant major standards. Sika also provides the technical support only global companies can, with both corporate and local experts available for advice and support, in both corporate and local testing laboratories to find the best solutions, based on their decades of sealant experience.


  • Classification: EN 15651-1 25 F HM EXT-INT CC
  • Classification: EN 15651-4 PW 25 HM EXT-INT CC
  • Floor joints: EN 14188-2
  • Chemicals: EN14187-6


  • Classification: ISO 11600, 25 HM
  • Floor joints: ISO 11618
  • Durability: ISO 19862
  • Staining: ISO 16938-1
  • Outgassing: ISO14644-15/VDI2083 –ACCm Class -4.5/-6.8
  • Biological: ISO846/VDI2083-18


  • Classification: ASTM C920 Class 50
  • Staining: ASTM C1248-4


  • EC1Plus, A+, M1, LEED v4 & solvent free

9. References

References and case studies from around the world provide security that Sikaflex® PRO-3 Purform® will deliver exactly what it promises. Check out a recent project here:

Learn more about Sikaflex® PRO-3 Purform®


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