Roof Moss on Areas Shaded by Solar Panels

[jff6791]

I've noticed a significant amount of roof moss and algae growing on the asphalt shingles below my solar panels which are SE facing. Has anyone else experienced this and come up with a method to remove it and prevent it from coming back. Most typical solutions seem to be brushing and spraying various solutions which isn't very feasible without dismantling some or all of the array.

[Will792]

When I replaced my 5 years old system with a new one I also noticed plenty of algae, underneath panels. For the new system I placed zinc metal strip on the roof, underneath top edge of the panels. It has been 2 years so far and I do not see algae growth. Honestly I was skeptical that it would work since reviews on the efficiency of zinc strips is very mixed. It seems to be working for me so far.

I used Geocell 4500 to glue zinc strip to roof shingles. It was relatively easy.

[SunEagle]

When I replaced my 5 years old system with a new one I also noticed plenty of algae, underneath panels. For the new system I placed zinc metal strip on the roof, underneath top edge of the panels. It has been 2 years so far and I do not see algae growth. Honestly I was skeptical that it would work since reviews on the efficiency of zinc strips is very mixed. It seems to be working for me so far.

I used Geocell 4500 to glue zinc strip to roof shingles. It was relatively easy.

I understand that some shingle manufacturers use zinc shavings mixed in with the colored granules to help algae from growing on a roof. For some reason zinc will inhibit that type of growth even when the shingle is not covered by a solar panel.

[jff6791]

My roof was replaced about six years prior to solar panels with a GAF Cool Color product which had EnergyStar rating at time for high reflectivity. I don't see any mention of zinc additive in the present specs and based on results probably didn't have it when mine were installed. I see some treatment products out there consisting of granulated zinc which you spread along the ridgeline and allow rain to spread it down. Not sure if this could deal with the amount of existing moss we have under the panels right now however.

[SunEagle]

My roof was replaced about six years prior to solar panels with a GAF Cool Color product which had EnergyStar rating at time for high reflectivity. I don't see any mention of zinc additive in the present specs and based on results probably didn't have it when mine were installed. I see some treatment products out there consisting of granulated zinc which you spread along the ridgeline and allow rain to spread it down. Not sure if this could deal with the amount of existing moss we have under the panels right now however.

Well I worked for GAF for about 6 years back in the 80's and back then we were adding the zinc at our Mobile plant to reduce roof algae. It wasn't spelled out on the packaging then because we were told it was something our competitors did not know about. I don't know if they are still doing that but my guess it worked back then so why not now.

[peakbagger]

Zinc strips are available from most roofing supply outfits, they just get secured up under shingle near the ridgeline and covers the entire roof surface under the strip. I have heard in salt spray environments along the coast that the strips can "wear out"

[jff6791]

Zinc strips are available from most roofing supply outfits, they just get secured up under shingle near the ridgeline and covers the entire roof surface under the strip. I have heard in salt spray environments along the coast that the strips can "wear out"

That raises the question as to whether this or some other means should be installed proactively before the panels to avoid a condition that will compromise the roof and probably void most warranties.

[Ampster]

That raises the question as to whether this or some other means should be installed proactively before the panels to avoid a condition that will compromise the roof and probably void most warranties.

I think the same question could be raised about the proactive need for critter screens. My installations in various parts of California have not been bothered by critters or moss but I am sure there are plenty of places where that is an issue.