How to clean this clay tile roof (SoCal)?

mjb_exterior_cleanin · February 13, 2020, 11:51pm

I believe I’ve read over all the related posts on tile roof cleaning. This one had some good input but no answer.

I just moved to LA and not sure about these clay tile roofs.

What’s this black stuff?

I sprayed some EBC (degreaser) and rubbed it a few times with a surgical towel. Below is what it looked like (after the 1st round):

Then, I did the same thing 3 more times, and this is what it looked like:

There’s still some black remaining (maybe 85% gone).

Does this need bleach? If so, a 4% mix or something? (I should have had bleach on me)

Would you need to lightly pressure wash it off afterward?

Thanks in advance!
-Micah

marinegrunt · February 14, 2020, 12:03am

It doesn’t matter what you’re cleaning if it’s organic it needs bleach. Obviously be sure bleach is safe for the surface you’re cleaning. That looks like mildew and bleach won’t hurt roof tiles.

MuscleMyHustle · February 14, 2020, 12:03am

Degreaser . Oh boy!

mjb_exterior_cleanin · February 14, 2020, 12:25am

Mildew, of course, why didn’t I guess organic? Some reason I was thinking it was dirt (don’t ask why). I’ve never cleaned these roofs. Okay, thanks, Brian.

Yes, no kidding, I was thinking this was dirt (not organic). Pretty pathetic.

MuscleMyHustle · February 14, 2020, 12:29am

don’t leave your home without bleach. If you do go back and get it.

Chesebro · February 14, 2020, 12:38am

Welcome to LA, Be sure you have proper insurance to clean roofs here in socal… People here sue for fun

mjb_exterior_cleanin · February 14, 2020, 1:04am

I’ve never seen so many billboards and about 25% of them seem to be lawyer ads.

I should know better. Excellent advice.

Seandz · February 14, 2020, 3:26pm

I did a flagstone patio last year (early on in my learning, which I’m clearly still actively doing) and I hit black spots on it with every f9 product made because my dumb ■■■ didn’t have any sh with me. None of the f9 products touched it. Went back with SH, dumped month old 12.5% on it, let it dwell 10 minutes and scrubbed with a brush and it came out. For organic sh can be better than muriatic acid!