# Mold and alge cleaning



## dougwerner (Feb 4, 2010)

Does anyone have a good recomendation for cleaning mold and alge from older shingles?


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## 4 seasons (Dec 31, 2009)

bleach is recommended. Are we talking asphalt or cedar?


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## Grumpy (Oct 29, 2008)

We do some cedar roof cleaning. Thre realy isn't any market in my area for roof cleaning of asphalt shingles, however what little there is gets eaten up by the "power washing" companies and there are many of them. 

I can only comment on cedar. 1) Too much bleach will stain an area. Woops, don't ask how I know. I mix the biocide bleach into my power washer's detergent spout. 1 gallon will do a whole roof no problem. 2) If using bleach you will want to water down where the downspouts drain so as not to kill any grass or plants. I recommend saturating before working, at lunch and then again after working while cleaning up. This will save you on costly landscaping repairs. 3) Set your powerwasher on low low low. Did I say Low? You really don't need much PSI. 4) Roofs are extremely slick when wet BE CAREFUL! 5) Never spray upslope, only down slope, as the water would shed in a rain. 

I always try to upsell a cedar preservative. There is alot of useless crap on the market, but IMO anything not *oil based* is a waste of money. Alot of guys are simply applying a solid color stain using an airless sprayer, this doesn't revitalize the cedar one bit, it just hides any flaws. The product I prefer is TWP 200, or Total Wood Protectant. It is expensive, but it's worth it IMO. The oils will actually soak into the wood and replace any natural oils the wood may have lost. 


As an added bonus and to set myself apart from the power washing companies I will throw in flashing caulk for free as well as replacing up to one bundle of missing or damaged shakes for free. Well to be honest it is marked into the cost, but I have yet to see a 15+ year old cedar roof that did not need a few shakes repalced. http://reliableamerican.us/services/cedar-cleaning.htm


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## Jasonthompson (Jan 25, 2010)

I use this stuff call Jomaxx u can get it at home depot and it work pretty good


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## buildpinnacle (Apr 18, 2009)

Any good oxygen bleach product. Sodium Percarbonate. It works the same as chlorine bleach but is not harmful to you, the plants, the dogs, etc. This product is present in most backyard deck cleaners....I know, deck cleaners on a roof. It works.


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## Johnk (Oct 30, 2008)

One part bleach,3 parts water,1/4 cup trisodium phosphate.(gallon)


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## jamesfl (Jan 21, 2009)

here you go,

http://www.gaf.com//Documents/Steep...-TechnicalPointsObservations-474-473-5009.pdf

James


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