Steel screw in columns
Power driven galvanised steel columns are an alternative pier system to copper chrome arsenate (CCA) treated pine piles. The columns have a fluted flange (helix) on the ends. This enables the column to drill itself into the ground.
The system is an engineered system. It requires an accreditation certificate to ensure acceptance by building authorities.
These columns have a potential corrosion problem, which is difficult to assess timewise. Aggressive (heavy, reactive polluting) chemicals in the soil could attack the columns. The galvanised coating can also be removed from the column if coarse boulders, gravel or sand are hit during the drilling process. Removal of the galvanised protection coating can accelerate its corrosion.
