roof algae stains

See discussion and solutions at www.askthebuilder.com.

The black streaks and stains are probably black algae, which can be removed with oxygen bleach as well as other commercial cleaners which you will also find mentioned in that website.

Best way to prevent black algae growth is to expose the roof to full sun, if possible. Copper will also poison the surface and prevent algae growth. Copper flashing applied at the roof cap will work as well as algae-resistant shingles, which contain copper particles in the mineral coating granules. The flashing works by rain washing copper molecules over the roof.

I had a similar problem (moss) on my asphalt shake shingles which I recently replaced with algae-resistant shingles.

Black algae is obviously more noticeable on light colored shingles and practically all the homes in my neighborhood with light-colored shingles have black algae growth; particularly on the north side.

I have used awg 12 copper wire (not insulated) across the roof at about 4' spacing. It eliminates algae growth. Cleaning a discolored roof I agree with Bluestone. To prevent future growth the copper works really well and will last for your lifetime - not just the roof. I have even used this on (not so popular anymore) heavy shake roofs and not only did it prevent growth it killed the existing algae. I removed the discoloration with a small pressure washer -- 1300Ppsi. Works well. Lotsa labor though

I believe a company in Lexington, KY has a solution.

It is environmental protective coatings.

www.enviroprotectivecoatings.com

check with Mr. Homer Hart.

I think he has something for this.

Recently, we have tested a product called TC-1000 with excellent results to remove Black Algae. This is a liquid that you spray on the algae and algae stains and within 24 hrs, everything turns to white chalk like powder. The poder can be washed with a pressur jet and it removesd everything cleanly. Black Algae is very stubborn as its like grass, survives due to the rots penetrating micropores. You can remove the surface form but it will grow again due to the roots embedded in the substrate. With TC-1000, we have seen that even the roots got destroyed.

This product sounds an awful lot like something that was described to me, not too long ago, by an Inventor who produced a chemical back in the l990's that was designed to remove the stains caused by Mold and Mildew. I would like to learn more as to where I can obtain this product so as to test it. Have seen far too many products that simply bleach the surface and do nothing to remove the Algae itself. I am really looking for some kind of Killer that will penetrate and maybe leave behind some type of residue so when the Algae attempts to return it will encounter a time-capsule that will kill it before it gets a good hold. There more I can learn about how the current "solutions" are made, etc., the easier it may be to design a really effective means to eradicate this mess once and for all!! It's really difficult to find the foot-prints of those who have gone before when the environment changes so quickly. Thanks for directing me to something that sounds promising!! Who makes it and how much does it cost?

This product is manufactured by Oil Field Tekniks, India. You may contact them on admin@oilfieldtekniks.com. Probably they can mail a sample to you. We purchaed it for a swimming pool application to remove black algae and the price was US$ 5.00 per liter. It can be sprayed on the algae using a simple house spray. All the best.

Thanks to everyone who has offered suggestions!! This is a very important matter affecting me and with so much actual junk out there I had no idea where to begin. Has anyone tried "200 mg's Erythromycin Phosphate in 10 gallons of water?" There seems to be as many varieties of chemicals available as there are people willing to sell something to me! In any case, I really do appreciate the responses, and other emails that have been sent to me. The suggestion of a product that turns to powder after penetrating to the roots is one that I am definitely following up on!! The area where this stuff will be going is very large and it sure will be much easier to be able to see where the product has been - after it dries - rather than to rely on someone's memory as to where they have sprayed, etc..

Good Luck to you sir.