I have 3 year old asphalt based shingles that are turning black... mostly in the shaded areas. I assume that it is some kind of mold that is spreading. Is there anything I can put on it to kill the mold without hurting the shingles or their original grey color? Thanks, Jaydee
My dad used zinc strips on his roof, the mold eventually went away. I used Jomax on mine, it worked ok. Didn't remove it totally but it looks nicer than it did.
If you do a groups.google.com search for "mold on shingles" you'll be greeted with more info than you'd ever care to know.
Good luck!
snipped-for-privacy@tampabay.rr.com wrote:
Bleach will clean it. Try in an inconspicuous area first to make sure it wont discolor the granules.
To keep it from coming back google zinc mold shingels and read up about different products. Here is an excerpt from the first google hit.
A. According to Nick Kerzner, of Kerzner Remodeling & Construction in Oconomowoc, black or very dark roof stains are caused by a hardy type of algae, Gloeocapsa magma (often referred to as blue-green algae), which grows on the roof and feeds on the limestone filler in asphalt shingles.
"The algae often originate in standing water, as well as in lakes and ponds," Kerzner said. "Wind, birds and other wildlife carry the algae spores to roofs from the water sources, and then from roof to roof."
Most stains begin on the north-facing side of the roof, where the lack of sun keeps the roof from drying out completely. The algae normally grow for quite some time before stains are noticed.
"Five to 10 years is not uncommon," Kerzner said. "As the algae grows, it holds more moisture on the roof, thus accelerating the growth process." Advertisement
Installing a zinc or copper strip at the ridge of the roof inhibits the growth of these organisms by coating the surface with zinc or copper ions as the rainwater flows over it.
"However, installing a strip will not remove existing stains, so consider using a product that will clean organic stains," Kerzner said. "Many of these cleaners are used by power washing the shingles, so extreme caution should be used, especially on older roofs."
Once the stains are removed, the metal strip should be installed under the ridge cap, ridge vent or under the first row of shingles for maximum protection.
The strips can stain siding, but the stains are easily removed unless they're on very old or porous vinyl siding.
"More than likely, any runoff will be contained in the gutters," Kerzner said. "As for which one is preferable, zinc seems to be the more common, so availability is easier on ready-to-install products and it will probably be less visible as it ages."
Inviato da X-Privat.Org - Registrazione gratuita
Thanks cas,
I'll check out the local HD and see what I can find. Are the zinc strips a common item? If not, where would you suggest I look for them? Sounds like a combination of things might be needed. I do have a pressure sprayer but don't want to damage the shingles. Thanks, Jaydee
I had mold on the sheetrock in my basement, and I thought bleach would clean it too. I think I killed the mold, but it had no effect on the black color. Maybe a scrubbrush would have helped instead of sprayer.
I ended up repainting it but that won't work with shingles.
>
check here .. .. ..
no connection .. .. .. just a satisfied customer .. .. ..
I had/ have similar problem. This spring I put zinc strips up- got from this site- they seemed to have the best price- but check around yourself.
I don't have any expericence but isn't there a way to lower the pressure all the way down to the city water pressure. The tool seems very limited if you have to use it at high pressures.
This has been covered so many times it's nauseating. Do a search.
I am in FL and have a tile roof - neighbor has shingle roof. We have a man who comes around once a year and sprays our roof with a mildewcide of some kind. It kills the stuff and when it rains after the treatment, the stain washes off with the rain. Call around and ask some place like Home Depot. I know they sell it because I bought some one time and used it to get the mildew stains off my pool deck where the water ran down from the gutter. Clorox will probably bleach the stain and won't hurt the color of the shingles...but the mildewcide will help stop it from growing for awhile.
My house gets those mildew spots on the side of the house where the sun doesn't reach until later in the day.
Abe wrote:
HomeOwnersHub website is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.