The subject buildings are 1970s low-rise block of domestic apartments in North London of conventional brick built construction featuring a stepped out entrance section leading to central stairway.
Detailed Case Study:
The buildings are three storey blocks with repeating front façade featuring a stepped out entrance section leading to the stairway serving wings either side.
Each short wall return (dogleg) protruding corner have been largely rebuilt and further cracking to the junction to both rebuilt and old brickwork was noted.
Defect
The returns are approximately 450mm, it is recognised that short wall returns (dogleg) on long façades can perform as one long span with regard to hygro-thermal movement taking place that can develop cracking on the front corner, as is apparent to the buildings with cracking to the front corner to both old and rebuilt noted.
Discussion
From Action Wall Ties findings it is apparent bearing in mind the large area of brickwork façades that have been constructed without the benefit of any expansion joints that the cracking noted is due to seasonal moisture, thermal expansion and contraction i.e. hygro-thermal movement.
Solution
Action Wall Ties remedial works are designed to provide a cost effective, long term solution ameliorating all the defects noted that retains the existing appearance with the minimum effect to the occupants and impact on the environment.
Action Wall Ties completed a remedial scheme that provided a viable repair by introducing expansion joints, bed joint reinforcement crack stitching.
Action Wall Ties experienced skilled operatives install remedial wall ties either side of the proposed joint before fixing the saw track to the wall and connect a hydraulic twin diamond bladed saw set to cut a 10mm wide joint to the full depth of the external skin.
Saw in Operation
Cut Joint ready for de-bond sleeved ties and soft flexible joint
Action Wall Ties services are available to clients in the South East i.e. in