Zinc strips

I have a an at leat 25 year-old ashphalt shingle roof on the house I recently purchased. There was moss growth, not real bad, in between and on the bottoms of the shingles on a few of the roof slopes. I applied roof moss killer product (Lillys Roof Moss-Out) or something like that. It was the liquid concentrate that you mix with water then spray onto the moss with a pump sprayer. I waited several weeks, per the directions, for the moss to start dying, then went up and meticulously and carefully scraped the remaining semi-dead moss off of the shingles with a putty knife.

Now I want to do something to help prevent re-occurence of moss growth, so am considering installing those roof zinc strips along the roof ridges which you can get in 50-100’ rolls from the hardware store. Was researching them a little, wondering how effective they might really be, and of course came up with conflicting info, some saying its the way to go, some saying no that because they are flat and smooth and thin and can cup and thus the rainwater that leeches off them will not be evenly distributed so you’ll still end up with moss, so they’re not a good solution. Also, from what I read in the installation instructions they usually want you to nail the strips onto the roof through the shingles with ring-shank neophrene-washered roofing nails. But I don’t know if I would be comfortable with nailing through the roof, even with the neophrene washers, for fear that creating nail holes through the roof regardless is just asking for water leakage.

Any comments on the effectiveness of these zinc strips, and/or tips on the best installation technique? thanks

To be honest if the roof is 25 years old it is near its life cycle. Zinc strips are the least of the worries. I would honestly spend the money towards getting the tree cut away from the roof and possibly a new roof with ar protection. You will only by a couple of years doing what you want to do. Scraping on shingles is not a good idea. I would just replace the roof being its 25 years old knowing they did not make shingles that lasted longer than 30 years back then.


Do not use that type of zinc strip. The nails through the shingles is asking for trouble.

Chicago Metallic makes a 3’ zinc strip that is nailed under the shingle.

They work. We install a lot of them. There are always spots where it will not keep it 100%. In the last 8 years I have one small spot on one roof that moss has grown. Not bad for all the zinc strips I have installed.

The zinc strips will work on your present roof. Then they can be reused on your next roof.

The AR shingles are good for 10 years. So even if you use the AR shingles at 25 years you will need the zinc strips.


You do not need trees to grow moss on a roof.

I tear off 25 year roofs that are on for 35 years all the time.

Thanks for the all the advice, guys. Lefty, it seems like the strips you mentioned from Chicago Metallic would be the way to go. Plus, as you said, if and when I get a new roof I can re-use the strips. The installation instructions for those (as seen on their website) says to lift the row of shingles and nail the strips underneath them. I wonder whether my shingles can endure such lifting to enable such nailing without cracking or other damage, though. Comments?


You can test a tab of the shingle. This will let you know if it can be done.

You can use daps of Geo-Cel chaulk to hold them in place.

You sound like you are handy and careful. You followed the directions for the cleaner. Then you scraped the rest off. This took patience to not destroy the shingles. Sliping the zinc strips in should be something you can handle.

Get a strip of aluminum. See if you can install that. If you can get the zinc strips.

Thanks Lefty,
I live in a relatively remote town in SE Alaska where the local builders supply and/or hardware store doesn’t stock either the Chicago Metallic zinc strips or the Geo-Cel caulk (should I need it). And I’m pretty sure when I ask them about it they won’t know where to get it. I went to the Chicago Metallic website and shot them an email asking them the easiest way I might be able to purchase the strips in my area, but haven’t heard back yet (of course its still to early to expect a reply). Have any suggestions meanwhile otherwise how I can get some here? And what is this Geo-Cel caulk you spoke of? What kind of special caulk is it, how does it apparently work well for such an application if turns out I shouldn’t try to nail?

Also, we do have a few roofers in this town that perhaps I could ask. Maybe they’ve heard of these strips and know something about how to get them here…


I live in Anchorage. drop me a pm and I will let you know what brand of zinc strips we use.


Hi Roofboy,

Is it some kind of secret?

Hello Lefty,

No , I am not at the shop so I don’t have the info right away.



Geo-Cel sticks good to most materials. It will hold the zinc to the shingles. It is the best I know of to prevent them sliding down your roof.

I find that GeoCel has a whole line of adhesive and caulk products. Which specific GeoCel product would be good to adhere the strips to the composition ashphalt shingles?

An insurance contractor estimator I know took pictures of a roof that got hit by lightning and the lightning ran along the zinc strips and popped the ridge up that was nailed on top of it.

geocell rp400,or2300

I’m not a metal roofing guy, so don’t hold me to this… I’ve been told that you should NOT apply silicone to a hex head screw (the kind with the rubber washer) as the silicone for some reason unknown to me eats the washer away.

I would assume that the rubber washer on the nails provided with the coil of zinc is about the same; silicone would eat it up?

I also wonder if you can refresh the zinc by touching it up with some sandpaper, either fine or coarse?

As for the GeoCel, it’s definitely a silicone product & NOT caulk; two different things entirely.

Hi RanchHandRoofing,

You have to show me where Geocel is a silicone product.

Zinc does not need a freshing up. What makes you think it would?

This may be all said and done with by now but if you want something that will definitely do a good job and is less expensive and less effort I would recommend using the moss killer granules. Most popular moss killer granules or powders are just zinc also. If you use the same brand as the one you mentioned in your first post (get the granules not the liquid stuff) the tubes say that applying them to your roof before moss grows will prevent moss. Zinc strip may help a little bit for a little bit but applying the granules once a year is always effective and you don’t have the upfront investment of buying strips that don’t last more than a year or two. You also don’t have to mess with the in-depth application or worry about hiring an installer that you would with zinc strips.
I actually have some pictures on my website that show how ineffective the strips can be:www.practicalpressure.com/Do_Zinc_Strips_Prevent_Moss.htm

Hi Practical Pressure,

I would not recomend you install zinc strips either.

What are you making those out of?