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Tested and Proven

TÜV Rheinland LGA Bautechnik GmbH rigorously tested and approved the Underbold roading system by conducting comprehensive evaluations of its performance in real-world conditions. The testing process included assessing the additive's effectiveness in enhancing soil adhesion, durability under various environmental conditions, and overall contribution to road stability. Their expert analysis confirmed that the Underbold system meets stringent safety and quality standards, ensuring reliable and long-lasting road foundations. This certification underscores the system's suitability for modern infrastructure projects, reflecting TÜV Rheinland's commitment to excellence in construction quality assurance.


Underbold® is a liquid additive developed for the faster, easier and more affordable construction of road foundations.
When constructing a new road, parking lot or driveway; Underbold® is mixed in with the existing soil making the soil particles more adhesive to the bonding agent. The bonding agent is then mixed into the soil and settles around and between the particles treated with the Underbold® mixture.


✔ Up to 30% cost savings
✔ No need for filling materials such as crushed stones and gravel
✔No long journeys bringing in bituminous materials
✔Projects take a shorter time to complete
✔The completed surface is more durable

Multiple Advantages

  • Time: Considerable time savings due to shorter construction time of the overall project.

  • Cost: Significant cost savings due to faster and more efficient construction. Less material and machine use.
  • Durability: Increase in load-bearing capacity + Increase in modulus of stiffness + Increase in elasticity + Complete frost resistance.
  • Environmental: 100% natural ingredients. Less exhaust emissions due to less material movement. Reduction of CO2.


  • Preparation: (1) Leveling of the surface, removal of the organic top layer, preliminary profiling.

  • Tamper: (2) Mixing in the emulsion. Crushing and mixing the soil with the Underbold POD30 water mixture. Preliminary profiling.
  • Application: (3) Distribution of the binder on the surface.
  • Mixing: (4) Mixing the soil with the binder.
  • Profiling: (5) Final profiling of the desired slope.
  • Compaction: (6) Maximum compaction of the mixture.