Cleaning a Shingle Roof (Mold and Black Stains)

[Matthew B.]

Has anyone had success cleaning a shingle roof? I have one with the black mold stains and streaks. Someone recommended something called neutral copper fungicide power. I have no idea what it is or where to get it. Any suggestions?

[Peter Sanchez]

Mold doesn't grow on inorganic objects.  Sorry to say, but it's probably growing in the plywood under the shingles and a cleaning isn't going to cut it. 

[Account Closed]

 @Matthew B. Blue/green algae can cause that

Copper fungicide is in lawn and garden at lowes or Home Depot 

Copper sulfate works

[Matthew B.]

Algae is what I meant. Whatever causes the stains on the shingles.

[Matthew B.]

@Account Closed 

Does the fungicide work instantly? I actually found some roof cleaner on Lowes.com. I'm not sure how well it will work.

[George P.]

Peter is wrong.  I used to have a roof cleaning business.  I still have chemicals that can be sprayed on the shingles then pressure wash the roof and looks like new. there are many individuals in Florida that still do it.  it's a big business due to the staining on Florida roofs...  

[Account Closed]

I mixed copper sulfate

Here is a link

http://www.todayshomeowner.com/remove-prevent-algae-stains-asphalt-shingle/

[Matthew B.]

@Account Closed 

What would you recommend?

[Matthew B.]

@Account Closed 

I spoke too soon! I see it now.

[Matthew B.]

I'm reading online that a 50/50 solution of bleach and water will do the trick. Just soak it down, let it sit for 20 minutes, and rinse with a garden hose.

[Martin Scherer]

Bleach solution  worked well for me.  I tried bleach and scraping and found it worked no better than simply spraying the bleach.  Just purchse one of the back pack plastic garden sprayers and really soak the roof.

I am assuming firbrglass/asphalt shingles not wood shingles.

There is also a zinc product that works well and if you are installing a new roof you can purchase zinc strips that are installed beneath the cap shingles with a small 1/2 inch band showing it will keep the black stains from starting.

[Brian Hanson]

I live in Central FL and reroofed with light gray 3-tab shingles.  Ive pressure washed it once and will do it again before I put it on the market next month.  The shady areas are now black and when I've washed those the "clean areas" look dirty so I end up pressure washing the whole thing, and it looks like a new roof. Water/bleach solution works well but is more labor intensive, pressure washing is faster but you have to be careful that you don't do it too often as it will knock the granules off the shingle, reducing the life of it.

[George P.]

nothing u can buy over the counter.  these were chemicals that I used to buy from a guy in Tennessee.  there are are few people throughout the country that make them. 

call this guy from Ohio and ask him..  

http://m.pressuretek.com/chemicals.html

[Michael Herr]

Originally posted by @Peter Sanchez:

Mold doesn't grow on inorganic objects.  Sorry to say, but it's probably growing in the plywood under the shingles and a cleaning isn't going to cut it. 

 Not sure about organic vs. Inorganic. (don't know my chemistry well enouh to know what contains carbon),  but you implied that shingles are inorganic and cannot have mold growing on them. 

Standard asphalt shinles are organic. 

I had a property with a roof that was shaded almost all hours of the day. It looked like it had black streaks and had voth green and grey moss? Growing on it. 

I sprayed it with something sold at a home store made for thia purpose (sorry don't remember the produc, or even the store) It worked great.  

[Kent R.]

DO NOT PRESSURE WASH! If you pressure wash, you will remove granules thus shorten the life of your roof.

There are companies that will clean shingles using solutions and low-pressure washing however, a less costlier way is to use the 50/50 bleach/water solution, let it sit and then rinse with the garden hose.  Be sure to soak down any plants or shrubs that are close to the drip line beforehand because the bleach will have the same effect on them that it does on the mildew.

You will notice tile roofs as well as shingle roofs in Florida with "black" on them because dirt (which is organic) accumulates and allows the mold/mildew to grow.

[Stephen S.]

There are roofing cleaning products to use - they clean and kill the 'mold'.  Then use a low pressure  (less than 1000 lbs. )  pressure washer to get down to the basic shimgles.

You can also paint shingles.

All of the above is Exactly why I only install metal roofing now. <g>

stephen
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Originally posted by @Matthew B.:

Has anyone had success cleaning a shingle roof? I have one with the black mold stains and streaks. Someone recommended something called neutral copper fungicide power. I have no idea what it is or where to get it. Any suggestions?

[Matthew B.]

I'm going to try the 50/50 bleach and water solution tomorrow. I'll let you all know how it turns out.

[Roy N.]

I guess there is an advantage to having long winters with -30 temperatures and lots of snow .. all the moss on the roofs has to start anew each year ;-)

[Matthew B.]

Success!

50/50 mixture of bleach and water removed the stains almost instantly. The garden hose took care of what was left. The roof looks 100% better!

[Doug W.]

I had the roof on a fix and flip professionally cleaned via a low pressure solution. I'm sure that the solution was as is described in a lot of the posts of this thread. Basically they sprayed it on (really soaked it) and then within about 7-10 days, including a couple of good rain storms, the difference was really noticeable. The shingles looks great.

I would also warn you, as I noticed others have done above, that the chemicals can potentially hurt plants. This includes when it blows in the wind. I'd also be careful when it comes to the cleaning solution getting onto cars, garbage cans, etc. The stuff could end up bleaching your clothes later if you rub against the car or garbage can. I speak this from experience.