DOES SILICONE TRULY WASH OFF IN THE RAIN?
We have heard the objection time and time again that silicone, and roof coatings in general, wash off in the rain. Because people believe this, they believe that it’s risky to install silicone if there is any chance of rain in the next few hours because it will wash off. Let’s see if this is true or not, and what it means for you.
The History of This Myth
More often than not, when someone brings up this question with us, they have worked with acrylic coatings in the past. As soon as we hear that, we know why they are concerned. Acrylic coatings do wash off in the rain quite easily. That is one of the major downfalls of acrylic coatings. If there is any rain in the forecast on the day you’re considering applying the coating, you better wait until the next day. A good rain on a wet acrylic coating means your parking lot is getting coated rather than your roof. A history of working with acrylics is the common origin of this objection.
Is It True of Silicone?
So, while acrylics wash off, is it true that silicones do too? No! Silicones don’t wash off in the rain. In fact, the more moisture the better. Silicone coatings are moisture cured, meaning the more moisture in the atmosphere, the faster they cure. Rain doesn’t wash the coating off, it actually cures it in place.
Now, this doesn’t mean you want to apply silicone in the rain. The rain will leave dimples in the coating that are harmless but are unsightly. If it’s raining, don’t start applying silicone. But if you’re applying silicone and it starts raining, don’t fret; your project isn’t ruined.
Most of the time, this objection is the result of someone assuming silicones and acrylics are similar or the same. Once we establish that the two products are very different, this objection tends to disappear.