10 Edison Place, Bromley
Christchurch, New Zealand

Voids/Concrete Floors

Overview of Void Filling using Foam Concrete

Foam Concrete is an ideal void filling product being flowable enough to get into very small voids and light enough to equal an existing ground density or just heavy enough to displace water. As the density can be varied depending on the application there are many possibilities.


Voids under Concrete Foundations and Floors

  1. The advent of the Christchurch earthquakes has left many homes needing foundation and floor relevelling. Various techniques can be employed to relevel a house foundation and concrete floor but invariably, the result is that there is a void under the floor that needs to be filled. Foam Concrete is a cost effective way to fill the void and re-support the floor.
  1. The tailings material commonly used as a fill material in new concrete floor construction proved to be a less than ideal product for the purpose. After being exposed to shaking during the earthquakes, tailings would compress. This phenomenon, along with the process of mechanically jacking the foundation and floor back to level would result in a, sometimes substantial void under the floor that requires to be filled. Foam Concrete will flow to completely fill any voids under the floor restoring structural integrity.
  1. In other situations, a concrete floor supported on piles may remain level, however due to settlement, the tailings or compacted fill has settled and left a void under the floor. Considering that the foundation and floor was piled originally because of weak soils, an added benefit of using Foam Concrete as a void fill is its low density which will not impose additional loads on the sub surface soils.
  1. Canterbury Foam Concrete Ltd can carry out void investigation and propose a solution for void filling and crack sealing.