Screw piling, underpinning and masonry reinforcement   thumb_piling

This property was a semi detached house built of solid masonry walls, off strip footings and featured a render to the first floor.  The property was understood to have suffered blast damage during WWII and was now suffering from subsidence.

 Topbond proposed a remedial scheme which featured screwed piles below ground level in conjunction with masonry reinforcement above ground level.

 Internally the existing concrete floor and fill were broken out and removed. This allowed the property to be underpinned using cast insitu reinforced concrete needle beams installed from inside the property.  The needle beams were centrally positioned above the CHANCE screw piles with one end being cast beneath the existing foundation and the other positioned beneath then new reinforced concrete floor slab.

 The piles featured a triple helix on the lead section and were hydraulically screwed into the ground until the desired torque was achieved.  The benefits of the screw piles are that they virtually eliminate noise and vibration (a drawback with impact driven piles), minimises the disposal of excavated soil and allows the pile to be easily withdrawn if required.

 Externally the screw piles were placed at key points around the perimeter of the property.  These piles featured a galvanised steel lifting bracket which was placed on top of the screw pile and then hydraulically jacked up beneath the existing foundation, before being bolted to the concrete strip footing.

 The new reinforced concrete floor slab contained 2 layer of mesh reinforcement and was cast with Lafarge Agilia self compacting concrete which was pumped into placed from the delivery wagon.

 Topbond are approved installers for Chance screw piles and Helifix masonry reinforcement.