A good product to consider is roof be clean see www roofbeclean for product information.
How to install zinc strips on roof.
Install z stop zinc strips 50 foot roll to keep it from growing back.
You still need to remove the existing moss algae.
This article gives instructions for installing zinc strips at the ridgeline to inhibit moss.
Step 4 maintaining the zinc strips.
If possible it is best to slide about 1 4 under the roof ridge vent roof cap or the top row.
Posted for a friend.
I conducted a fairly long term experiment by installing zinc strips on a moss covered garage roof and showed before and after photos after the zinc had sixteen months to work its magic.
In these cases installing a second zinc strip approximately halfway down the roof slope is recommended.
These chemicals will create an environment that will prevent moss growth.
The zinc metal strips are made from a variety of metals.
This picture shows nails through the zinc strip.
In november of 2011 i wrote a blog post about using zinc strips to prevent moss from growing on the roof or possibly to kill moss.
Like rooflover said the zinc strips don t work and they certainly don t work on existing roofs that already have moss algae on them.
If the roof extends for more than 14 4 27 m down from the ridge where the zinc strip is installed re growth can occur.
On roofs with moss algae mildew or fungus the existing growth must first be removed by pressure washing or brushing then the root systems must be chemically treated and destroyed see magazine articles for bleach solution.
By installing the strips on the ridge any water that runs over them will trickle down the roof carrying the zinc chemicals with it.
It looks like they have nailed through the zinc in to the roof.
Preventing roof moss with zinc strips in this video this old house general contractor tom silva shares tips for keeping a roof free of moss and mold by this old house.
Wouldn t that allow water through the roof.
The roof must be cleaned of moss and or mildew.
The strips are then coated with zinc.
Copper strips however do work and should be exposed 2 and placed every 10 up the roof.