Under SANS 10400-XA each area of the country has different recommended R-values for insulation depending on the climatic region it falls into.
This Rvalue will determine what material thickness is required. In most unprofessional installations the materials used are very thin or otherwise ineffective materials are used–resulting in the R-value being very low, thus leaving the homeowner unhappy with the resulting poor performance of the installation.
Typically, Eskom recommends a cellulose thickness of 135mm for Johannesburg and 115mm for Pretoria.
Thermguard cellulose fibre insulation is the simplest, most cost effective way to improve your homes ambient temperature saving electricity, saving you money