Both the underground and the ground part of the formwork are strengthened by columns, which are clogged into the ground in the ground to the shields and attached to the boards with large nails. In addition to fastening columns to the shields, columns are additionally strengthened by wooden slopes. One end of the slope is strengthened by nails to the vertical column, and rests against the other against the supporting column, driven into the ground. In addition to this fastening, if the foundation has a large ground height, the shields are strengthened by spacers that hold the formwork frame from compressing.
