Lurking beneath the Edendale Hospital in Pietermaritzburg, are subterranean basements, that are crumbling, leading to the structural integrity being undermined.

Dr Shepstone laid the foundation stone in 1951 and the hospital was completed in 1954. It was designed with a maze of plinths, underlying the basements.

These areas are closed off with little or no ventilation, which has allowed severe Spalling to build up over 60 years.

The KZN Health department has a 10 point National Hospital Revitalization Plan. A sub section of this plan is to improve general hospital conditions.

Spalling Worx (Pty) Ltd has been awarded the contract to repair these badly spalled concrete areas to the basements. Anderson Vogt Consulting are overseeing the specifications and quality control.

Limited Access

The limited access has a bearing on a number of things:

  • Lighting – Access to electricity is a problem due to distance. Generators cause exhaust fumes, and due to the compact space, cannot be used. A solution was to use 12 volt LED lights, whereby the worker carries his own battery pack. These are recharged daily.
  • PPE – A full complement of PPE was supplied by www.safetyetc.co.za. Disposable masks with one way valves have been used, to keep out dust caused by repairs, but allows freedom of breathing.
  • Temperature – Whilst the outside temperature can get up to the middle 20’s in winter, the basement temps are around 2-3 degrees. Workers have to allow for these vast fluctuations, by layering clothes.
  • Work space – The general workspace is 700mm high. This makes general conditions almost unbearable. No electrical equipment can be used due to excessive dust, so mechanical hand held tools are used.


Many people do not know most untreated concrete is quite porous. Without proper sealing or waterproofing, it will readily absorb water. If the concrete is located in a well-ventilated dry area, this may not be a major concern.

For example, if your concrete driveway is well-constructed, has a good granular base and good drainage, it should easily dry after a heavy rain. This will prevent the slab from becoming saturated and remaining wet for an extended period of time. If these conditions are not favourable, or if you have major cracks in the surface, the concrete can remain wet long after precipitation occurs. In the worst cases, this moisture can cause the cracks to expand and the surface to spall.

The conditions are perfect in the Edendale basements. Little or no ventilation has caused moisture to build up over 60 years, leading to the integrity of the foundation slabs to crumble from Spalling.

This seven story building is at risk of eventually collapsing.


Sika has been awarded the supply of product. Whilst there are options depending on depth of repairs, the following specification applies:

  • Remove all loose and friable concrete from the substrata
  • Mechanically chip back to at least 2cm behind exposed steel reinforcing.
  • Mecahnically abrade rusted steel back to bright or firm steel
  • Replace steel according to engineers specifiations if necessary
  • Apply Sika Armtec 110 to rusted surfces
  • Build up with Sika Monotop 615HB

For in depth specification, please contact the writer on kevin@spallingworx.co.za 083 600 3037 www.spallingworx.co.za

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