Newman’s were called upon by a commercial property management company who own various trading estates across London.
Many trading estates in London are still Victorian brick built structures that have stood the test of time and are still fully functional. The masonry construction of most of these structures is built using 13 inch solid masonry laid in English bond using lime mortar. This type of construction is a strong bond which will allow slight movement.
We were called out to attend site as a matter of urgency due to the crack rapidly widening and in some places was over 10mm’s wide. We carried out a structural survey free of charge the same day and designed a repair specification that would restore the structural integrity without any major disruption to the business operating in the building.
Crack Repairs, North London
We used our own mobile scaffold tower alleviating the need for traditional scaffolding enabling us to be on site just two days after the initial survey.
To repair the crack in the brickwork we installed 14 No masonry beams across the crack which was drilled back into the left and right pillars. This method of crack repair not only crack stitches but distributes the loads imposed and distributes them across the masonry preventing further cracking.
Crack Repairs, North London
The parapet wall was secured using 1.5m grout ties which were installed vertically down through the brick work which saved huge costs in a rebuild.
The repair was guaranteed against failure for 10 years. The repairs lasted only 2 days allowing the business to remain fully operational.
Subsidence is a common structural defect which puts structures in serious jeopardy and at risk of collapse.
Subsidence is common across the South East of England and in areas where the ground conditions are formed up of clay. Clay absorbs lots of moisture during wet periods causing it to swell and lift the foundation and once the ground dries it shrinks back to its original state or smaller which causes the foundation to drop.
Subsidence Repairs
There are other causes of subsidence such as vibration from machinery, road traffic, trains etc. As well as vibration other factors such as changes in the water table, failed drainage or incorrect foundation types and depths.
Newman’s are specialists in carrying out subsidence repairs using bed joint reinforcement and piling solutions in order to repair structures with minimal disruption.
Retaining walls are built to retain soil to unnatural slopes separating two elevations. Often they fall into a state of neglect and structural defects occur putting the retaining structure into jeopardy of collapse.
There are various techniques used to build a retaining wall and the three common techniques used are called Gravity, Cantilevered and Sheet Piled. There are various other techniques used such as gabion basket, and buttressed walls.
With changes in the earth pressure on the retaining wall, changes in the water table and areas of structural defect retaining walls tend to fail. The damage caused by a failed retaining wall is severe and can lead to injuries to persons within the vicinity causing them to be crushed. It can also be damaging to property as often the retaining wall is retaining soil that the property is built on forming an integral part of the structures foundation strength. A slip in the soil can cause your property to subside. And you may be liable for legal action if you have failed to maintain your retaining wall.
How to identify a Structural Defects to a Retaining Wall?
Cracking and bowing are the main defects that will be evident when a retaining wall fails. This can lead to the wall to collapse completely due to the loss of structural integrity. Retaining walls rely on their ability to act as one structure and with a fracture this will prevent the structure from retaining the soil.
Cracking On Wall
Before cracking and bowing of the wall are evident you should check the condition regularly of the wall after the winter months or periods of heavy rainfall. It is important to check that the pointing is still strong and not defective as this will allow the penetration of moisture. It is also important to check the condition of the face of the brick any spalled bricks should be replaced as again this will allow the penetration of moisture which can cause a structural defect.
How Can My Retaining Wall Be Repaired?
In the early stages of a failed retaining wall it is possible to use helical bar combined with high strength grout as incorporated in the Twistfix System, which Newman’s are approved installers and designers of. With this method it is possible to install lengths of helical bar to create masonry beams which will allow the structure to act as one panel again.
In cases of severe outward movement we employ various techniques of restraining the wall by introducing platypus ground anchors that tie the structure to the ground using high tension cables and pattress plates preventing further outward movement. In instances where the loads are extreme piles have been driven in to the ground to resist the outward movement.
If your retaining wall is suffering structural defects ensure you contact Newman’s for a free survey and repair specification.
