1 Introduction:
When you come to look at and assess a concrete pool for re coating there are some aspects that you need to take note of apart from the internal surfaces. By doing so you will begin to understand the pools situation relative to other issues that may impact on your coating and its long term success. If you ignore these factors, then you run the risk of missing important clues, which may save you and the client much angst.
2 Concrete Shell:
When a pool is designed it will be with a compressive strength suitable for its intended use and with sufficient re enforcing steel correctly imbedded. As an example the engineer may specify 30 Mpa strength and at least 50 mm concrete cover for the steel work. The actual onsite results may not be such. Poor shotcrete application techniques, insufficient compaction, and movement of the steel reinforcing chairs, all lead to porous areas of concrete, insufficient cover and many other factors. These over time may show up with leaks, failure of the finishes and rusted steel work, staining the surfaces.
3 Look out for:
When assessing the pool in question check the following in addition to the normal items:
If you see any of the above factors then it’s highly indicative of water being in, around or under the pool and this may impact on the success of the coating, now or many years later on.
4 Solutions:
The best coating to use in a concrete pool, is one that is both water and vapour proof as it’s going to keep the pool (salty) water away from the reinforcing steel and save the pool owner issues to do with concrete cancer.
Epotec NT, being a high build coating fits this requirement well.
However if there are issues with moisture within or under the concrete surface, there is a chance that in time it will cause the coating to blister. This can be hard to forecast, unless you see signs as indicated on page one.
If you have seen these signs or have concerns then you should:
As an alternative you may want to suggest the use of a porous finishing system, such as a trowel on finish which generally lets water in and out of the pool surfaces. However these being “open”, collect stains, dirt, algae and also let calcium nodules form.
5 Summary:
Water is insidious and can make one’s life difficult. More so if these aspects above are not noted and then considered. Most times there are no issues and the project goes well, as does the performance of the coating. However every now and then, situations arise, which are quite easy to detect beforehand. When so noted and the issues discussed with the pool owner a resolution can be forthcoming or at least the situation monitored so that if matters arise later on, there are no surprises to argue over.
Contact us for more details.