If you're a roof cleaning contractor that has been in the business for any length of time then you've surely had to deal with the issue of evaporating chemical.  This really isn't a problem during the cooler months, but it can be a major time and wallet killer during the hot days of July and August.  There's a way to overcome this problem, however, and it's much simpler than you might have thought.

First you should understand why this is happening.  Shingles are designed to reflect sunlight and heat away from the roof surface, thus keeping the home cooler inside.  In this process, however, a huge amount of heat builds up on the actual shingle surface.  If you've ever been cleaning a roof on a 90 degree day and have reached down to touch the roof with your hand then you know what I'm talking about.  This heat can be so intense that it's similar to a stovetop on a low setting.  What happens when you sprinkle water on a hot stove?  It evaporates in a flash.  This is exactly what is going on with your disappearing roof chemical.  On hot days most of it is probably evaporating before it even has a chance to begin cleaning the roof.

As I mentioned, there is a trick to avoiding evaporation and it's an insider's secret that I'll share with you now.  Before applying chemicals to the roof, drag a garden hose up to the roof surface and spray the whole roof down with water.  Give it a very thorough soaking, and then immediately commence with chemical application.  This will effectively lower the surface temperature by a large margin so that chemical evaporation can be avoided.  Don't worry about diluting the chemical because most of the water will be gone by the time you drag the chemical hose to the roof surface and begin spraying.  Just make sure to do these two steps in quick succession because if you wait too long after applying the water the surface temperature will quickly rise again.

By utilizing this method during hot days you can save a lot of money in chemical costs, and you'll save time, too.  Applying chemical three or four times because of evaporation will be a thing of the past.  In this business it's important to learn the tips and tricks that the pros use, and I hope you'll take this one to heart.