Considering a good portion of Christchurch is built on reclaimed swamp, its no great surprise the importance a good solid foundation plays in your new build.
Most commonly a Ribraft or similar pod floor will be the most suitable choice for the project.
Ribraft floors are a light weight foundation with polystyrene blocks in the centre, concrete beams and top slab which keeps them low in weight but high in strength as well as giving them a good insulation rating.
Usually the ground beneath the ribraft floor is excavated to "good bearing capacity" which is determined by a geotechnical engineer, once excavation is completed, typically backfilling of the excavation can commence using aggregate compacted in lifts to replace the unsuitable excavated material that was dug out prior, if the ground is really bad the engineer may call for geogrid (a type of plastic webbing) and biddim cloth (stops silt coming up through the aggregate) to be placed at the base of the excavation and sometimes geogrid in the layers of backfill for extra strength.
Once the earthworks for the Ribraft is complete, the Ribraft slab can then be constructed ready to start building.
Typically Ribraft foundations sit on the ground, not in the ground which makes them seismically stable.
Here at TBT EARTHWORKS LTD we can provide both the earthworks and the Ribraft floor construction services.
Posted: Thursday 21 July 2022