A range of Sika products was specified to seal and waterproof concrete surfaces at the Mafikeng Provincial Mental Hospital.
The new reservoir at the Mafikeng Provincial Mental Hospital was sealed and all flat concrete roof areas and concrete walkways on roofs of the hospital were waterproofed with high-performance products supplied by Sika.
The Sikadur-Combiflex SG system, which allows for irregular movement, was used to seal all construction and expansion joints inside the reservoir. The system consists of a modified, flexible polyolefin (FPO) waterproofing tape that is adhered to the concrete substrate by Sikadur-31 DW, a modified, solvent-free, filled, two-part epoxy resin adhesive. Then 200m of Sikadur-Combiflex tape (250mm wide) and 240l of Sikadur-31 DW were applied, both which have international approval for drinking water.
All concrete floors and walls of the reservoir, covering an area of 100m2, were subsequently coated with SikaTop Seal-107 ZA, a two-part, polymer-modified cementitious mortar slurry, comprising a liquid polymer, cement-based fillers and special admixtures.
The flat roofs and walkways were waterproofed with 3 500 rolls each of Sika BlackSeal T-140 PG, with a plain bitumen surface, and Sika BlackSeal T-140 MG, with a slate granule broadcast surface. Both products are torch-on, sheet waterproofing membranes, flexible to 0oC and based on APP (atactic poly-propylene) modified bitumen that is reinforced with polyester non-woven fabric.
A Sika BlackSeal system provides high tensile strength, resistance to water vapour and mechanical impact, and good dimensional stability. The range has passed stringent accelerated ageing tests for long-term exposure to ultraviolet (UV) radiation and elevated temperatures.
Despite severe flooding that disrupted the time schedule, the ease of application of the specified Sika products greatly assisted the contractors from TDS Waterproofing.
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