Anyone with experience cleaning asphalt roof shingles?

[Tom52]

The roof on our house has asphalt shingles that are about 10 years old. The shingles are in very good condition but they have quite a bit of black staining on them that really detracts from the appearance. Reading on the net it appears that what I actually see is algae caused by humidity and extreme shade.

I would like to clean the shingles so I asked the roofer who originally installed the shingles if he could make any recommendations to remove the algae. He was not aware of any product that would do this. So I went to the internet and read that the ARMA (asphalt roofing Manufacturers Assoc.) suggests the most effective method is a 50:50 mixture of laundry strength liquid chlorine and water sprayed on with a typical sprayer, let set for 20 to 25 minutes and then rinse off. My concern with this is what, if any, affects this would have on plants and grass as a result of the rinsing. Obviously, the original mixture would be even more diluted but I don't want to ruin plantings or burn up the grass.

Anyone with any experience using the chlorine bleach solution?

The other possible solution I found on the internet was a product at www.cleanertoday.com which says there solution is safe for plants, but the downside of course it the cost. While not unreasonable at roughly $150 for materials to treat an entire roof is much more costly than the chlorine bleach. Of course, I am always concerned that I would pay the bucks and the product would be a dud.

Any with any experience using this product or can anyone recommend a product that successfully used?

 

[freedomatlast]

The plants and grass will be fine if you rinse with lots of water and then rinse with lots of water again.

 

[Just_Steve]

I have used this Spray & Forget 32 oz. Super Concentrated Cleaner with Hose Sprayer Not Refillable-SFSRC-6Q - The Home Depot

Spray it on, let it dry and when it rains it reactivates, read the instructions it takes time to work.

 

[braumeister]

I got rid of my roof algae and moss with whatever cleaner I found at Home Depot (spend five minutes scrutinizing the products on the shelf and you'll find an appropriate one).

Then I installed a strip of copper under the top row of shingles and the problem never came back.

 

[calmloki]

Protecting plants: spray them down wih the hose before starting treatment so if chemical gets on them it is instantly diluted.
I've used bleach for black algae - it works fast. Last couple years I've been trying washing soda. Very slow acting, but less worry for the plants - I use it on decks and sidewalks also. Be advised - you will leave white footprints in the house if you walk through the wet powder or spray if you mix and apply with garden sprayer.

Edit: lotsa pennies at roof ridge work also!

 

[CRLLS]

I have used this Spray & Forget 32 oz. Super Concentrated Cleaner with Hose Sprayer Not Refillable-SFSRC-6Q - The Home Depot

Spray it on, let it dry and when it rains it reactivates, read the instructions it takes time to work.

I have also used "Wet and Forget", a similar product, on the north side of the house siding and decks. Both have a lasting effect of about a year.

 

[travelover]

I have also used "Wet and Forget", a similar product, on the north side of the house siding and decks. Both have a lasting effect of about a year.

Me, too. Bought it at Costco. Works for a year or two.

 

[SteveNU]

I used a product called Roof Wash from home Depot or lowes a few years ago too clean the roof of algae and stains. Just spray it on brush it in with a broom and rinse it off. It took a few weeks to really see the results but it cleaned it very well and still looks good.

 

[Mulligan]

My neighbor had his shingles cleaned by a cleaning company last summer. Cost a few hundred bucks. They had roof soaked in a foam for a short period of time and washed it off. Those shingles are about 12 years old and they look brand new. Other neighbor thought they had new shingles put on. It took all that black growth off completely. I then had them power wash my house for $150 cash. Saved me a lot of work and money well spent too as I am lazy.

 

[Bamaman]

What ever you do, be careful up on the roof. Most modern houses have steep roof planes that are difficult to get around on. I was just cleaning gutters when my ladder fell over, and I broke both legs and was in bed 7 weeks.

Whenever re-roofing a house, always make sure you purchase the best shingles money can buy--3 tab architectural style. My father put 20 year shingles on a lake house saying "I won't be around to replace them." They lasted 15 years and he was still around. Then I had to replace them 10 years later after storm damage.

It's just a shame shingle manufacturers don't produce products that hold up better against mold and algae. But then, they'd sell half as many shingles. Try that 50/50 bleach solution to see how it works, but be sure you're wearing throwaway clothes as they too are going to get bleach spots. And a respirator might be required if you don't apply the stuff on a windy day.

 

[wrigley]

I got on top of my roof (single story house) with a 2 gallon garden sprayer filled with bleach and water and started spraying. The shingles looked brand new when I was done and it was cheap.

NOTE: I did this quite a few years ago when I was younger and bullet proof!

Mike

 

[haha]

What ever you do, be careful up on the roof. Most modern houses have steep roof planes that are difficult to get around on. I was just cleaning gutters when my ladder fell over, and I broke both legs and was in bed 7 weeks.

Oh that is terrible! Congratulations on your recovery, that doesn't always happen.

Ha

 

[btdt22]

I have used a hose type sprayer with water and household bleach with good results. I refuse to climb on a wet roof or ladder under any circumstances. I also suggest using surgical gloves and eye protection.

Don't expect to see immediate results as it takes some time for the bleach to "bleach"

 

[Bir48die]

I live in a wetter part of the U.S. but I buy a large box of cheap detergent with phosphates and sprinkle at the top of the roof line. Cleans and kills moss.

 

[calmloki]

I live in a wetter part of the U.S. but I buy a large box of cheap detergent with phosphates and sprinkle at the top of the roof line. Cleans and kills moss.

Psssht! What's an Oregonian know about moss?