Very often we come across this question when we discuss about waterproofing activity. We strongly believe that Waterproofing is one of the very critical activities and requires highest possible supervision; following are the reasons, for why we feel so……
Ponding tests are usually done for 48 hours, and it is very easy for the waterproofing to survive 48 hours even with lowered specs – i.e., say that the as per specs Dry Film Thickness(DFT) is 1mm, and applied DFT is around 0.6mm; in this case if you do ponding test, the result will be a pass. But the durability becomes issue. So ponding test alone is not enough for waterproofing. Following are the points need to considered along with ponding test to achieve a successful waterproofing application,
- Mixing ratio
- Coverage – kg per sq mt
- Surface preparation
- Application procedure
- Protection measures
Let’s see why these short coming can happen in the site:
Waterproofing materials that are available in the market are numerous. There are number of companies & with many line products, the applicators are mostly clueless when there is a change in material or the site conditions.
It goes like this - most of the applicators are usually gets experienced with one type of material (Ex: Cementatitious) in a normal site conditions (Ex: sunken toilet with or without spout). When these guys are provided with some other material (happens when they change the work places / contractors) they will not have actual specs for the new material – i.e., mixing ratio, setting time, coverage. Also when there is a change in site condition like waterproofing on sloped screed or with excess bore packing, they tend to miss out the finer details.
Another reason can be the contractor’s mind set to save on material. That is, the contractor can give a successful ponding test with 60% material itself against the actual specs. So the Supervision plays a major role.
Another important part is uniformity of application – In some cases, material consumption would have been ensured by some processes, yet things can go wrong in terms of uniformity of application. This can be ensured only through proper supervision….
