Good to see that people care about what they do. However, unfortunately it can and does take months for some reactions to occur. I have worked for Impey (But prior to Waterguard). I have seen when reactions have occurred resulting in a thick Black tar coming through grout and ceilings. Trust me. They put installation instructions in with the kits for a good reason. And of course there is the guarantee to consider. Divert from what they state at the cost of it.