Pkspigs,

We use a product called Shingle Shield here in Cincinnati to clean roofs, you can purchase it online at www.egutter.com You probably have the black mold algae reoccuring on your roof, it thrives in high humidity areas especially in the south. Zinc strips do help deter the algae. The algae usually likes to grow on the north and west sides of the roof, since that is where it gets less sunlight (unless your in a shaded area). You might have to add more zinc strips on your lower shingles too, to increase the amount of zinc molecules working on your roof. If you need more info. on how to clean your roof or if you are looking for more info. post your question here or email me and I'll try to help you out.

Thanks,

John Allen

I cleaned them this date with shingle shield, did absolutely no good whatso ever. The zinc strips seem to be in good shape on the peak of the roof, I don't know what to do next? can you helP?

How did you apply Shingle Shield and what method did you use to spray it off? Sometimes the light pressure of a water hose isn't enough.

Another product that I came across but haven't tried is Kleen Roof. You are suppose to be able to spray this stuff on your roof and the rain just washes away the stains, I don't know how well it works but it's not to expesive to try. If you do try it please let me know how well it works. I will post a link below for you to check that product.

Getting back to Shingle Shield, there hasn't been a roof yet that we have not had results with, not all roofs come 100% clean, but I would say we make a 95% to 100% improvement, so maybe you can tell me how you are using the product.

John

Here is a link that might be useful: Kleen Roof

John

Can you give more information on where to find and use the zinc strips? Is it true that you can just cut up flashing instead into strips and get the same results? I have what looks more like very thin moss growing on my roof (yellow green but dies to a lichen-like white. Will the zinc strips eventually knock this out or do I have to start with a clean roof. Thanks!

Cut up flashing? No. The strips must emit zinc oxide in order to prevent the growth of algae, moss or fungus.

You must start with a clean roof! Sodium Hydroxide is the active ingredient of Shingle Shield.

Michael

John, I used the power washer with the chemical setting, which is a low PSI, I used it stronger than directions called for, but NOTHING happened. Just a little brownish greenish run off after I let it sit and the rinsed. Like I said, my zinc stips seemed to NOT do anything for the problem after approx. 2+ years? Rgards for your help. P

pkspigs:
If you can post/link some pictures it would be useful. Are you near any indutrial plants that discharge into the atmosphere? I suspect that your "staining" might not be "typical" and therefore these suggestions are not working for you.

TSP/Bleach/Water
RECOMMENDATIONS
Discoloration of roofs caused by fungus or algae is difficult to remove, but may be lightened by spraying a diluted solution of chlorine bleach, trisodium phosphate, and water onto the roof. Solutions range from one cup TSP, one gallon bleach and four gallons of water, to one cup TSP and 2.5 gallons each of bleach and water. This solution can then be rinsed from the roof in 10 to 15 minutes. Do not scrub. Scrubbing will loosen and remove granules. After spraying be sure to thoroughly flush the roof and the greenery around the home (grass, bushes and shrubs) with water. The effectiveness of this type of cleaning may only be temporary, and the discoloration may recur. High pressure washing is not recommended due to the possibility of removing granules, thereby shortening the life of the Roofing System.

Here is a link that might be useful: Owens Corning Roofing - ALGAE GROWTH

I beg to differ. A clean roof is not necessarily required to kill moss.

I have a shake roof and some areas around the chimneys under the TV antennas were getting mossy (probably due to bird droppings). I didn't want to clean it off because harsh cleaning can damage a wood roof. I used a zinc containing spray, called "Moss-Kill" on my roof (I just used a garden sprayer for it), followed up by fixing zinc strips on either side of all the ridges.

I found the zinc strips by calling around to roofing supply companies. The product I found is called "Atomic 30" (30 is the atomic number for zinc). It's supposed to be pure zinc but I think it has a little alloying element to help it not be brittle.

Initially I stapled it to the shakes, but the staples tended to pull loose. So I followed up with short self-tapping 3/4 " long sheet metal screws, and those have held up very well (and the zinc strips keeps them from rusting.

Since all this, haven't had a recurrance of the moss problem. The roof still gets some algae growth, but that is reduced as well.

My understanding is that moss is worse than algae because the moss actively attacks the wood and accelerates its deterioration. The algae is more of a surface thing, I guess.

I agree with you about the moss, anytime we run up against the green algae or moss it seems to root itself to the shingle and many times when it's removed it takes the shingle granulars with it. Any green algae or moss is more difficult to remove (at least with the products we have tried). The black mold algae on the other hand doesn't seem to root to the shingle like the green algae does.

Another alternative to bleach is an Oxygen Based cleaner; Roof OX is an ideal spray on rinse off solution. The same company sells a contractor grade product used all over the South East, called Roof QSE.
Both are reasonably priced, and the company is helpful.

www.CleanerTODAY.com

Here is a link that might be useful: Industry leading roof cleaner formulas QSE & Roof OX.

Roof warrior,

Re-read the terms of agreement.

You agree not to make postings of a commercial nature;

Michael