Thirteen people lost their lives at the Pentecostal Holiness Church in Empageni, northern KwaZulu-Natal, when the church building’s front façade collapsed on them during a thunderstorm. Many more are hospitalised with various degrees of injuries.
“The front wall of the church collapsed at around 10.15pm as a result of a severe thunderstorm which was accompanied by strong winds in the area that had undermined the structural foundations of the building,” said Premier Willies Mchunu . ANA 22/4/19
Just how do severe thunderstorms undermine the structural foundations of a building?
An analysis of video & photographic evidence points to something additional and somewhat more meaningful; the absence of structure, poor building practice and incompetent builders. In this context the appropriate question to be asked is “how could a building like this be approved for public occupation by the local (Empangeni) building control authority?”
Members of the South African architectural professions have been warning for decades that incompetent and corrupt building control authorities are endangering the lives of citizens by allowing sub standard buildings to be erected and occupied by the public.
This church building is one such building. It collapsed because it was built by amateur builders with no knowledge or understanding of fundamental structural systems or basic construction practices and, further, its construction was conducted without the knowledge of the local authority or was overseen by corrupt or incompetent officials who turned a blind eye.
It is clear that the building is neither new nor originally designed as a church. The buildings fire ventilators (1) are a clear indication that this building was built for industrial use and was re purposed as a church when the factory that it housed shut down or moved somewhere else. Alternatively the building was originally constructed somewhere else and then its steel portal frame disassembled and re-erected in its current position. Either way it is evident from its condition (2) that it is not a new structure.
But that is not the problem. The portal frame itself looks perfectly fine. The problem is the complete absence of structure on the front façade of the building. It should look something like the areas marked in white (9); two columns, in steel or concrete, and one crossbeam running from one corner of the building to the other. This missing structural element is not required to hold up the building; it is required for lateral strength - to keep the front façade’s brick wall from falling down.
It is highly probable that the original industrial building was clad in metal sheeting and only had brick walls up to about 1200mm. The absence of gutters (3) and rough cut end sheets with no overhang indicate that there would have been a metal sheeting bull nose system at the eaves. This building type is quite common in the area.
When the building was re-purposed as a church the decision was taken by the owners to clad it in clay face brick. The manner in which this conversion was undertaken is directly responsible for the collapse of the wall and the death of twelve women and one child. The wall was incorrectly designed and built.
We can see that the required structure (9) was not there because there are no signs of it anywhere in the rubble. But more telling - there are no witness marks at the points where said structure would have had to make contact (3), (6) and along (2).
We can tell that incompetent builders were engaged here by the manner in which the two front façade corners (4) and (7) were constructed. They are completely different and both are unresolved, allowing water to permeate the building envelope.
The absence of primary structural elements is as noticeable as the absence of secondary structural elements; there is no evidence of brick reinforcing wire (known as “brickforce”) having been used at all. Had there been any in the wall there would be evidence of it on the fractured wall (5) & (8).
One of the fundamental building practices which is increasingly ignored relates to brick wall strength and water. Cement requires water to bond to bricks at a molecular level – it is not glue. This bonding process goes on for up to twenty one days. When dry bricks are used, particularly dense clay bricks, water is drawn from the mortar mixture into the bricks themselves from where it evaporates. This invariably results in insufficient water remaining present in the mortar mix to cause a strong bond between the mortar joint and brick. This is particularly true if the masonry is not kept damp by regular watering, which is frequently the case; most building sites in KZN Natal are hot, windy and with limited access to water.
A well constructed brick wall will collapse, by demolition or natural causes, in panels of brickwork, not in clusters of single individual bricks. (11) The rubble evidence suggests that the mortar was poorly bonded to the bricks as most of the bricks are completely free of mortar and there are very few intact panels in evidence.
The collapsed wall was a 230mm face brick wall some thirty metres wide and nine or ten metres high built with no regard for lateral force stability, no regard for thermal contraction and expansion, built with poorly bonded bricks with no evidence of “brickforce” masonry reinforcing. It was simply a matter of time before it failed and it could not have failed at a worse time.
This tragedy and loss of life could have been avoided had the building owners appointed a responsible architect or architectural technologist to oversee the construction of the building. KwaZulu Natal has thousands of qualified architects and architectural technologists of the highest standard and Empangeni is not some distant backwater in Africa; this should not have happened.