Crepe Myrtle Bark Scale

This may be a southern thing, but has anyone run into the crepe myrtle bark scale? It is a problem we are having with crepe myrtle trees where they get covered in black moldy soot and covers the tree everything around them. Its a black sticky mess. I’ve had to deal with it on gutters and driveways and have had success getting them clean. Gutters have to be scrubbed to get it off, but it will eventually come off. I’ve tried SH, some degreaser, and a few other things and nothing really seems to work that great other than scrubbing and scrubbing. Pressure on the driveway seems to do the trick. Anyway, I don’t do roofs, but have a buddy that is wanting me to try and get it off his roof. I tried a realtively hot mix of SH in a pump up sprayer on the corner of the roof where it is and nothing. Any suggestions? As I said, I don’t do roofs, just trying to help a buddy out that is about to put his house on the market. Here are a few photos

In the last pic, if you look at the left corner of the roof you will see the black stain. Looks better in the pic than in person.

I just use SH mix

How hot of a mix are you using on it Kenny? I was at about 4% in a pump up and it didn’t touch it.

Reminds me if this post:

How much did you use?

According to my math, I was about a 4% mix with elemonator. Hit it twice and nothing.

4 per cent should do it. I have a commercial property that is infested with crepe myrtles and usually 1-2 per cent does it. With a pump up you may not be able to put down a heavy enough coat