Technical/Subsidence

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Subsidence is usually caused by damage to the subsoil caused by external events such as leakage from drains.

The existing footing is exposed and locally broken out to allow the Duralift bracket to sit under the load bearing wall.

The lead pile is torqued into position as close to the wall as possible (practically touching).

Pile is installed using a torque motor attached to a mini excavator, skid or using a handrig where space is limited.

Each pile segment is 2.1m long. The pile is installed and the torque pressure is monitored.

A final torque pressure of 2000psi is required to lock the pile. Extensions are added until this torque is reached.

The pile is cut down and the Duralift bracket installed over the pile and inserted under the existing foundation.

The Duralift cross member is placed across the pile and two 24mm Gr8.8 threaded bars are placed in the slots with nuts top and bottom.

A certified hydraulic jack is placed on the cross member. An additional temporary member is placed above the jack as a reaction.

A load is applied to the jack (usually 5 tonne) and the plate is lifted until it takes the load of the footing.

The nuts are locked off above the cross member.

The jack is removed and the excess threaded bar is removed. The process is repeated at regular intervals along the footing. Each setup is backfilled with concrete (usually as part of the footpath reinstatement).

Subsidence is the downward movement of the ground supporting a building. It’s most causes include leaking drains, vegetation or landslip. The first and most obvious sign of subsidence is the appearance of cracks, in particular cracks that appear around the weak points of a building such as window and door frames.

Screwpile Ireland use an advanced piling system that can quickly and cleanly reverse the effects of subsidence.

Screwpile Ireland use a combination of helical piles and our patented Duralift brackets quickly and efficiently underpin any building that has subsided. As an additional feature, the Duralift bracket can jack up the building to its original position.

Subsidence