There are several products on the market that can remove the stains. Bleach is not one of them. All bleach does is take the color out of the mildew on the roof.
I would install Zink strips on the top row of shingles. Zink will help prevent these stains from happening. And will over time remove them. But for instant cleaning you need to use chemicals and a power washer.
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The power washing that is done on a roof is more like a broom washer on wheels not the wand from the machine itself. The broom has several nozzles as you would know. All sharing the pressure resulting in a much lower pressure then the machine delivers but more then a garden hose would do on its own.
Using bleach also has some very nasty draw backs. It can kill plant life. So its not suggested to be used.
Search the internet for companies that sell cleaners just for roofs. There are several of them out there and many work quite well.
I looked into getting into this business a few years back. As in the NJ area we have a lot of industry fall out staining roofs on every block. After looking into it for a while. It just did not make sense with the additional riders I needed for my insurance to put workers on a wet roof. Sure you can purchase wands and stuff to work off the ground on lower homes. But the larger colonials you had to be on the roof. And as you know, water and roof does not work. Carefully weighing the costs involved and the risk of the clients blaming me for the roof failure. Old story last one that touches it owns it. I steered clear of doing this.
My painter also looked into it. Seeing they were in the business of making outsides of homes look good. Well after about six jobs and two clients wanting their money back. He walked away.
Once roofs become stained from mildew the roof is already on its way out. The mildew is growing on the matting under the stone surface and once that begins the stones become very loose and begin to fall off fast. Cleaning this only makes the stones fall off faster.
Hey Gary, check out "Wet & Forget". I am no expert & have not used it personally, but am going to get some to clean my deck. Applied with a sprayer, website has retailers that carry it, like Ace.
zinc, lead, or copper strips will release ions that prevent growth of fungii and mildew and moss, but they will do nothing to remove it. The direct application of the powered form is needed to get rid of it.
I have used a pressure washer, but one must be VERY careful not to be damaging in the way it is done
Earlier this week I posted a roof we washed using Jomaps Roof and Deck Cleaner available at The Depot. This is an extremely concentrated Sodium Hydroxide solution that can be sprayed on the roof to kill and help remove mildew. The chemical does most of the work but is aided by using a pressure washer with a low pressure tip to remove the crud that remains.
If you want a new looking roof with the least amount of impact, it is the way to go.
I would install Zink strips on the top row of shingles. Zink will help prevent these stains from happening. And will over time remove them. But for instant cleaning you need to use chemicals and a power washer. ...»
The power washing that is done on a roof is more like a broom washer on wheels not the wand from the machine itself. The broom has several nozzles as you would know. All sharing the pressure resulting in a much lower pressure then the machine delivers but more then a garden hose would do on its own.
Using bleach also has some very nasty draw backs. It can kill plant life. So its not suggested to be used.
Search the internet for companies that sell cleaners just for roofs. There are several of them out there and many work quite well.
I looked into getting into this business a few years back. As in the NJ area we have a lot of industry fall out staining roofs on every block. After looking into it for a while. It just did not make sense with the additional riders I needed for my insurance to put workers on a wet roof. Sure you can purchase wands and stuff to work off the ground on lower homes. But the larger colonials you had to be on the roof. And as you know, water and roof does not work. Carefully weighing the costs involved and the risk of the clients blaming me for the roof failure. Old story last one that touches it owns it. I steered clear of doing this.
My painter also looked into it. Seeing they were in the business of making outsides of homes look good. Well after about six jobs and two clients wanting their money back. He walked away.
Once roofs become stained from mildew the roof is already on its way out. The mildew is growing on the matting under the stone surface and once that begins the stones become very loose and begin to fall off fast. Cleaning this only makes the stones fall off faster.
Sell them a new roof.
I have used a pressure washer, but one must be VERY careful not to be damaging in the way it is done
If you want a new looking roof with the least amount of impact, it is the way to go.
Best, Charles