3.3.2 The response to this question from a technical perspective is reasonably straightforward.
3.3.3 It is the view of the Inquiry that the primary cause of the collapse of the wall at Oxgangs school was poor quality construction in the building of the wall which failed to achieve the required minimum embedment of 50mm for the wall ties, particularly in the outer leaf of the cavity wall. The poor quality relates to all three of the following aspects:
• the direct laying of the bricks and the positioning of the wall ties;
• the direct supervision of the laying of the bricks and the positioning of the wall ties; and
• the quality assurance processes used by the sub- contractor and main contractor to confirm the quality of the construction of the walls.
3.3.4 All three issues were ultimately the responsibility of the design and build contractor in charge of the site.
3.3.5 It is also reasonable to conclude, based on the information in the meteorological records provided, that if the wall had been designed and built to the required appropriate standard it would have been able to withstand the level of wind loading to which it was subjected. The limited embedment of the wall ties in the outer leaf meant that the outer face of brick was simply pulled away from the inner leaf of blockwork due to the action of the wind.
3.3.6 Other factors that may have contributed to the poor quality of bricklaying are discussed in later sections of this Report.