Lichens are tough!

Did a customer’s patio today and it had some lichens I didn’t see initially until I hit it with my surface cleaner. It took a 15 degree nozzle to get rid of them, probably should have used some SH first.

SH wont really do anything for them.

Good to know. I guess pressure is it then.

It actually embeds its self in rock. If you try to remove it off a shingle roof you will pull chuncks of shingle off.

Once theyre dead, eventually they fall off and leave no real trace. But it take awhile.

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I was reading the Aussie soft washing page, there was a guy on there who recommends caustic mix using Caustic crystals.

I’ve had success with straight 12.5 on brick and concrete. For the brick it took over night. The next day they were gone. Concrete took a few hours I’m guessing. I use Cling on and straight 12.5

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I was basing it off racers roof mix. I think is usaully around 3%. It turned them white in about 5mins. He said they would fall off but it would take awhile. It might come off faster if you rinse. I had some on some brick i cleaned about a week ago. I hit it with a pump up sprayer it had a strong mix in it. Then hit with a 40 degree and flew right off.