Frozening clay, silt and sand are most suitable for the steel screw foundation. It can be used also in size 0-40mm rubble. When positioning the flange under the frozen soil layers, the steel screw foundation can be used for constructions without additional earth removal procedures or frost insulation. In more demanding purposes consider using proper ground inspection and a construction civil engineer.
Preparation work
Before installing the steel screw foundation check the possible locations of waterlines, sewers, telephone and electric cables. Your local utility company will assist you if necessary.
Getting started
The work is started by penetrating an iron bar to the ground to the depth of at least 50 cm to find out possible larger rocks or bedrock. if such obstacles are found, take special procedures for their removal. In large scale construction it is preferred to make the inspection or survey of the site before installing the first screw.
Installing the screw manually
The steel screw foundation can be turned into the ground manually with the help of an iron bar. The use of an L-shaped turning tool makes the procedure easy in slopeside, near the surface and walls and in tight corners
Installing the screw with hydraulic engine
The steel screw foundation can be turned in with a hydraulic engine found in vehicle lifters and diggers. Needed maximum moment (torque) in turning is 2000 Nm depending on soil properties.
The flange should be positioned when possible below the frozen soil layer. This secures the foundation against frost lifting.
Expansion part
The steel screw foundation can be made to match the different founding depths with adding up to 6 meter long entension pieces to the steel screw foundation pole.
Things to consider
If the ground water level is less than 1 meter below the surface, it is recommended to fill the steel screw foundation pole with suitable concrete, rubble or polyurethane foam. Otherwise frozen water inside can fragture and break the pole.
The steel screw foundation cannot be used in soil with rubble size over 50 mm.
The steel screw foundation can be used in frozen homogenous soil. If the installation is done with a hydraulic engine can the foundation be installed directly through asphalt.
If several steel screw piles are used they should the positioned in correct hight by turning the screws only clockwise. If necessary the piles can be cut to matching hight. The screws should not be turned counterclockwise unless that specific screw is to be taken away from the foundation.
When the construction is under ground water level or under water, the penetrating depth into the soil should be in hard and medium hard soil at least 2 meters and in soft soil 3 - 3,5 meters.