The technology in the marble plaster used in the construction of gunite (concrete) swimming pools has advanced in leaps and bounds over the last five to 10 years. Back in the day, pool companies used to buy their white cement and marble dust separately and then mix it together in the emptied swimming pool. After this was finished, they would plaster it to the pool surface. Although this practice is still used by some pool builders and renovators, the technology has changed significantly.
In the old days, we used to put additives like calcium flakes into the mix to heat up the cement and speed up the curing process. You may be surprised that we used to add dishwashing liquid into the mix to ensure a smooth and shiny finish.
Thanks to new and improved swimming pool plaster, we no longer have to add our own witch’s brew to the swimming pool plaster before resurfacing! Products such as PoolCrete (made by Cemcrete), have all the ingredients needed already in the mix.
There’s also a stringent process that needs to be followed when resurfacing a pool:
- After draining the swimming pool, an axe needs to be used to tap around the pool surface to listen out for hollow areas. Plaster that has separated from the ‘gunited’ pool shell must be chopped out and removed.
- 24 hours before plastering the pool, a slurry mix of white cement and FlexBond (a non-toxic latex-based liquid admixture) should be applied to the surface in horizontal brush strokes.
- The plaster should always be mixed at a ratio of six or seven litres of water to every 40kg bag of Poolcrete. Adding too much water to the mix will make the plaster sloppy and difficult to apply to the pool.
- The pool should be filled a few hours after the plaster application is complete, depending on the ambient temperature.
- The pool water must be balanced immediately after the pump is switched back on. Properly balanced pool water will give your plaster longevity and prevent black algae from growing on it.
