# Tackling yellow roof mold/pollen?



## MikeCalifornia (Aug 26, 2012)

I want to give a bid to a customer as an extra, already bidding the exterior. This house has a yellow mold on the roof tiles. My home has it as well. Might be pollen from the trees. Any thoughts on what it is and how to clean?

I can't upload to this page:
http://s872.photobucket.com/user/just_joes_by_mike/media/IMG_0405_zps54d4067b.jpg.html?sort=3&o=0


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## Roof Cleaning (Jun 29, 2011)

Looks like lichen and will not come clean with a non pressure method. That is a lot btw, that roof is a goldmine.

Two step chem cleaning is how I would tackle this...

Standard roof cleaning mix with TSP on this one applied thick to remove the gloecap and clean. You could add caustic at this point to the mix but I do not think it would do anything.

Spray the entire roof again, this time with the caustic mix (when completely dry of the roof cleaning mix) let it dwell, spray some more.

Come back the next day or at the end of the day and see if the lichen dehydrated and dying. You may need another application, you may not.

In my experience, the yellow will stay on the end caps (we call them elbows) and in the mortar. 

0040 and 2520 will be the last step to remove the lichen via softwashing and not full blast pressure washing.

Watch the caustic on the house, but I guess you are painting...

This is what we do before we paint a tile roof..hint hint hint....

Top dollar roof cleaning opportunity IMO
average bleach monkey will pw it or walk away...

cover everything under the sun and SOAK that mug. The yellow stuff will want to come off with a hose when it is ready. IF it doesn't, reapply chems and then check to see if it is ready.

We see this kind of lichen on beachside of town..mostly in the salt air.

hope this helps 

tom


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## Monstertruck (Oct 26, 2013)

The lichen actually let go enough for a soft wash in the end?
That is awesome!:thumbup:
Looks like a great opportunity.


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