The live oak branches produce a canopy over parts of the house, keeping things shady and (hopefully) reducing our electricity bills somewhat. Our hot, humid weather causes mold, mildew and algae to grow on the roof in those shady spots. I was thinking about getting up on a ladder and use my garden sprayer to spray some bleach up there to try to kill it and restore the roof to it's normal color.
Tricia talked me out of that Saturday morning and we headed to the local hardware store to see if there was a product made to kill the mold, mildew and algae that grows on roofs. Turns out, there is. It is a product called Spray & Forget. It's a little pricey at $44 per gallon, but if it works, that is reasonable. You mix it 1 part S&F to 9 parts water into a garden sprayer and spray it on the roof in the offending areas.
| Green algae on the roof |
You leave it on the roof. Green stains are supposed to disappear in 1-3 days and black stains over 3-6 months. I shifted my ladder over as I went around the entire house spraying. The worst areas were the east side, north side and west side. The south side has mostly sunshine covering the roof most of the time, so mold & mildew is not a problem in the direct sunlight.
I patiently moved around getting good coverage of the chemical on the green areas. When I finished, I still had half a gallon of the chemical left. I guess I'll save it and will use it again, if needed, to get areas where it didn't wipe out the mold.
So far, we're 24 hours post initial application. Although the product says that the green stains disappear after 1-3 days. So far, I'm not seeing any reaction. The stains are still there. It's early yet. I'll give it more time and report back with how this product works!