Poor or Expansive Soils

CUPOLEX technology, as well as CUPOLEX RIALTO, offers quick and economical solutions for poor soil condition and expansive soil or expansion due to frost and tough climate conditions, creating a raised floor or substituting expensive filling material. Over the past 3 decades, the idea of placing concrete over CUPOLEX® permanent void forms has become an increasingly popular foundation method, not only for site conditions involving challenging soils, but replacing conventional slabs that are not very well known to provide healthy interior environments.

Both slab on grade and ribbed structural slabs on grade can be created using CUPOLEX®. There are significant cost savings to the builder and owner by using the CUPOLEX® flooring formwork in the design of concrete slabs for residential, industrial, commercial and institutional applications in sites with structural site challenges and contaminated and low bearing soil conditions.

Fill Replacement

It is often necessary to replace a poor soil layer with more costly backfill material. CUPOLEX® technology makes it easy to eliminate or reduce the amount of gravel that needs to be imported and backfilled in the job site, and replace it with a ventilated void.

Expansive Soil

The unique patented concrete geometry which CUPOLEX forms minimizes the contact area on the expansive soil which does not restrain the potential swelling of soils beneath the slab. The minimal concrete in contact greatly reduces the lateral and uplift forces that are produced compared to a conventional slab bearing on the soil throughout the total slab area. The CUPOLEX slab in contact with the expansive soil ranges from 4% to 10% of the total slab area creating a space into which soil can expand without causing damage.

CUPOLEX® slabs do not restrain uplift forces and furthermore the dead loads of the concrete slab usually are greater than the uplift forces from the soil resulting in protection of the structure. In extreme swelling soil conditions, suspended self-bearing CUPOLEX® slabs would be constructed.


  • Lowers building costs
  • Speeds construction
  • Saves aggregate, concrete and steel
  • Solution for Structural Weight Limits
  • Minimizes the need for skilled labor
  • Provides a higher quality floor surface
  • Tested technology


  • Lightweight fill replacement
  • Expansive soil conditions
  • Extreme conditions and freezing soils
  • Concrete road construction

Products for Poor or Expansive Soils

Cupolex Products

Cupolex Rialto

Cupolex Products

Cupolex Rialto

Cupolex Products


Cupolex Products


Cupolex Products


Cupolex Products



San Vito al Tagliamento

PONTAROLO ENGINEERING SPA have been working in the construction business for over 55 years.
+39 0434 857010



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