Tower block construction began in the 1950’s with the first tower block in Britain being built, The Lawn in Harlow, Essex. The need for housing influenced the decision for tower block construction and it boomed.
The Lawn, Essex
Tower blocks are constructed usually using three methods; in-situ, Steel frame with infill panel and pre-fabricated panels. In theory all three methods of construction should have provided structures free from structural defect and with stand the test of time. In reality many high rise structures are in urgent need of refurbishment to ensure they do not enter a state of disrepair with the only solution being demolition.
With all three methods of construction there are common structural defects found that are often similar across the country. Cracking is usually evident within the external and internal fabric of the structure and the defects are often linked to one or more of these causes of movement, thermal movement, lack of movement joints and failed wall ties or inadequate wall ties. Poor construction methods during the build phase. Concrete failure as well is a common structural defect found which can be caused by many factors such as oxidisation of the reinforcing steel, the reinforcing steel being too close to the surface of the concrete which again causes oxidisation freeze thaw action and chemical reaction to name but a few.
Trellick Tower, West London
Newman’s are approved designers and installers of the Twistfix and Thor Helical repair systems combined with our experience we provide our own specifications for wall tie replacement schemes as well as crack stitching and masonry beams. We are also approved installers for Fosroc and Sika concrete repair mortars and resins, mastic and coatings.
When assessing the requirements for repair to tower blocks you should only use an experienced contractor and Newman’s surveyors and engineers have extensive experience carrying out structural surveys and designing structural repair programmes to reinstate the structural integrity to tower blocks. We have worked closely with many principal contractors and façade installation specialists to provide insurance backed repair schemes prolonging the life of the tower block.
We can also provide rope access surveys and installation on schemes that it isn’t feasible to supply and erect traditional access methods such as tube and clip scaffolding or cradle access.
We are currently carrying out a structural inspection and repair to a brick built railway bridge in North London.
Our client expressed concerns over the visible cracking and bowing present to the structure of which carries high speed trains into central London so it was vital that we acted quickly in order to carryout the inspection, design and implement a suitable structural repair scheme.
Bridge-reinforcement
To save time and cost in scaffold we opted to use our van mounted cherry picker that will enable our installation to be carried out rapidly, in less time that it would take to erect scaffolding.
The spandrel is suffering from de-lamination causing in some brickwork to fall from the masonry arch severely weakening the structure. the sofit which carries and distributes the loads of the masonry arch was showing signs of racking caused by vibration allowing water to penetrate into the structure causing defective pointing. the brick pier was also suffering from major cracking and separation.
We will be installing Twistfix helical beams at 300mm centres horizontally accross the masonry arch creating a grid pattern with the bars drilled 1.5m into the supporting pillars providing a reinforced structure distributing the loads. and over 4000 1.5m grout ties will be installed through the sofit into the arch pinning the sofit and preventing further delamination.
the works will be carried out so that the bridge remains fully functional and the road remains open and accessible.
At Newman’s we utilise modern methods of masonry repair to restore bowing walls and lintel failure to name but a few structural defects.
Our specialist services were called upon by a building surveyor managing the refurbishment of a Victorian built 1890’s semi detached house in Croydon, South London.
Bowing Building London
After completing our survey it was discovered that there was extensive outward movement to the front and gable elevations and with the loft conversion in progress the additional stress to the masonry was sure to cause severe movement.
Bed Joint Reinforcement
Over 30 Lateral restraint ties were used on the gable elevation alone into the first floor and the new loft floor to restrain the outward movement combined with bed joint reinforcement ensuring there would be no further outward movement.
Lateral Restraint Ties Installed
With the bed joint reinforcement being installed front the front elevation wrapped around the gable and into the rear elevation the lintel failure was repaired and the bowing restrained.
