Spray & Forget????

[higgledy]

Anybody have any expereince using this product to clean black algae from an asphalt roof?

=

[...............]

I dont know...... I FORGOT !!!!!!!

[higgledy]

You are funny!

...............@.................. wrote:

[roger61611]

That really looks suspicious. How do you have a FAQ and not mention what the active ingredient is ?

Here's an answer from This Old House, I'll leave it to the reader to decide who's more believable, some twit with a website selling mystery fluid or a PBS show that's been around for 20 years:

"The black mold-like stains and streaks that appear on roofs, particularly light-colored asphalt shingles, is actually a blue-green algae (Gloeocapsa magma). Commonly found in climates with warm, humid summers, it does no damage to the roofing, but it certainly does looks bad.

You could replace all the roofing with new shingles dark enough to disguise the staining, or with shingles laced with copper granules, which are lethal to algae. But that would only make sense if the shingles were worn out.

The less expensive solution is to spray wash the roof with a 50 percent mix of water and bleach to get rid of the algae. (No pressure washers, please. They're likely to damage the shingles.) Just be sure to wet your foundation plantings first, and rinse everything in clean water when you're done. Plants don't like bleach, and wetting them with plain water first protects them.

To keep the algae from coming back, insert 6-inch-wide strips of zinc or copper under the row of shingling closest to the roof peak, leaving an inch or two of the lower edge exposed to the weather. That way whenever it rains, some of the metal molecules will wash down the roof and kill any algae trying to regain a foothold on your shingles.

You can probably see this same principle working on roofs in your neighborhood. Look for chimneys with copper flashing; the areas directly below the flashing will be free of any algae stains.

The strips also work on roofs suffering from moss buildup. Just scrub it off first with a brush, then bleach as above. "

[Bob (but not THAT Bob)]

I'd skip the "spray" part and go directly to "forget it".

Investigate the reason for the problem, like an overhanging tree that should either be cut back or removed.

From my recent experience, where there's moss and/or algae, there's also rot and critters.

[CAMPFIRESKY]

replying to higgledy, CAMPFIRESKY wrote: I used SPRAY AND FORGET on my roof 3 years ago. The stains and algae on one side of my roof were terrible (probably due to the big maple tree I had removed). This stuff actually worked great. It took a few weeks for most of it to be gone and after a good winter, all traces were gone. I would not use bleach on my roof... damage to shingles as well as damage to plant life.

[edsamson60062]

The stuff I used was Wet and Forget. It took a few months but all the dark steaks disappeared.

[Leo]

replying to roger61611, Leo wrote: it's not suspicious at all. it's very efficient way to kill any type of mold and algae, the chemical is alkyl dimethyl benzyl ammonium chloride a common algaecide