REMEDIAL WATERPROOFING OF DEFECT WATERPROOFING BEHIND RENDER
This wall is constructed from besser blocks and has been rendered over. Behind the wall, there is a raised courtyard area and the breaches in the existing waterproof membrane behind the render were allowing some moisture to seep through as evidenced by smaller areas of render delamination.
The way besser blocks are designed, moisture is able to move through them. However, the steel reinforcements that run through the cores of the besser blocks are encased in cement which protects the steel from moisture. Due to the high alkalinity of concrete (pH of 12 to 13), the steel reinforcing bars are passivated by an iron oxide film (Fe2O3) that provides a protective layer to the steel.
To treat the moisture ingress:
Scope
1. Mechanically grind off render to the nominated section of the wall.
2. Install a water-borne epoxy waterproofing system
3. Perform leak sealing injection to the nominated length of the vertical joint between wall and house to stop water from seeping into the house.
Please note that the Water-Borne Epoxy (WBE) waterproofing system is susceptible to UV damage, so the client will render over the waterproofing now that we have completed our scope of works.
