Mossy roofs, ways to combat

[skeer]

So our property has a lot of trees… a lot! So when we bought the place I had the owner pay to put metal roofing on the largest shed which is now my shop.
But the next one down, roughly 20x12 is still pretty old shingle. It’s also much shadier than this one so a constant battle is between me and moss.
I read a few years ago that copper can kill it. So I desheathed one wire out of a 12ga cable and fixed it to the peak. Now, like three years later I’m learning it’s bunk or the coppers not big enough.
I’m looking for passive ideas, something I can put up there and forget about until we reroof it next year.

 

[FL Guy]

Sodium Hypochlorite will kill moss and hold you over til next year. May need a second application though.

 

[Garcky]

So our property has a lot of trees… a lot! So when we bought the place I had the owner pay to put metal roofing on the largest shed which is now my shop.
But the next one down, roughly 20x12 is still pretty old shingle. It’s also much shadier than this one so a constant battle is between me and moss.
I read a few years ago that copper can kill it. So I desheathed one wire out of a 12ga cable and fixed it to the peak. Now, like three years later I’m learning it’s bunk or the coppers not big enough.
I’m looking for passive ideas, something I can put up there and forget about until we reroof it next year.

That's not enough copper.

 

[skeer]

That's not enough copper.

Thought so, would a run off 1/2” copper pipe be sufficient you think

 

[Garcky]

Thought so, would a run off 1/2” copper pipe be sufficient you think

I don't know. Copper tape is used a lot for that purpose. However, it takes some time to work and is pretty expensive. Another solution, though, is to first get rid of the moss and algae already there. Careful power washing can do that. Then, copper tape at the peak on the shady side can help prevent it later.

 

[skeer]

Yeah just got done scrubbing and spraying with bleach. I’ll give the pipe a shot. I mean it’s all about surface area.. logically.

 

[Garcky]

Yeah just got done scrubbing and spraying with bleach. I’ll give the pipe a shot. I mean it’s all about surface area.. logically.

Worth a try. I had a lot of moss and algae on my north facing roof. I fixed it by re-roofing.

 

[skeer]

Yeah after the water heater I think next big ticket is a metal roof for that shed.

 

[alfadan]

I think its zinc that's supposed to kill it.
Just spray it down with the green bleach house wash stuff.

 

[paredown]

I think its zinc that's supposed to kill it.
Just spray it down with the green bleach house wash stuff.

This is what I remember FWIW. They used to sell flat zinc strips that you would slide under the tabs up near the peak, and the washing action would change the Ph. You might still need to clean off what is there, and then try the zinc to maintain. Looks like HD has a continuous strip for the job:

Master Flow 2.67 in. x 50 ft. Zinc Moss and Mildew Preventer Strip NMM50 - The Home Depot

Make use of this Master Flow Zinc and Mildew Preventer Strip for protecting against moss and fungus. Constructed of metal material.

www.homedepot.com

 

[Snip's]

Both zinc and copper will kill the moss....
I have copper on the roof peaks and valleys...
Flattened, the copper measures 8" wide...
Surface of the copper is needed to work...
Wherever the flow of rainwater off the copper misses, moss grows...

As a side note, I have moss growing in certain areas of my yard that gets a lot of shade...
I buy copper sulphate at Lowe's and mix the blue granules with water, and spray the moss...
Kill happens in a couple of weeks... Turns the moss from green to yellow and stops the spread...

This has approx 90% +_ copper sulphate...


https://www.weekand.com/home-garden/article/copper-kill-moss-18012837.php

 

[Solpainter]

Spray it with some Wet and Forget. May take a few months but you should be good for a year or more.

 

[skeer]

Both zinc and copper will kill the moss....
I have copper on the roof peaks and valleys...
Flattened, the copper measures 8" wide...
Surface of the copper is needed to work...
Wherever the flow of rainwater off the copper misses, moss grows...

As a side note, I have moss growing in certain areas of my yard that gets a lot of shade...
I buy copper sulphate at Lowe's and mix the blue granules with water, and spray the moss...
Kill happens in a couple of weeks... Turns the moss from green to yellow and stops the spread...

This has approx 90% +_ copper sulphate...


https://www.weekand.com/home-garden/article/copper-kill-moss-18012837.php

We’ve got lots of yard moss here too, but I like it. Ain’t no grass gonna grow in those spots anyway and if it does that means more mowing.

 

[skeer]

Think I’ll try the copper pipe, I’ve got an old J-pole I can desolder and use.

 

[yatg]

This is what I remember FWIW. They used to sell flat zinc strips that you would slide under the tabs up near the peak, and the washing action would change the Ph. You might still need to clean off what is there, and then try the zinc to maintain. Looks like HD has a continuous strip for the job:

Master Flow 2.67 in. x 50 ft. Zinc Moss and Mildew Preventer Strip NMM50 - The Home Depot

Make use of this Master Flow Zinc and Mildew Preventer Strip for protecting against moss and fungus. Constructed of metal material.

www.homedepot.com

Got mine from RotoMetals.com.
ZincArmor 3" Zinc Strip 50 ft Prevent Algae, Moss, Fungus & Mildew CB-07-E1
26.99 a roll as of 5/1/2023..
Bought enough to get free shipping.

 

[pcmeiners]

"Sodium Hypochlorite will kill moss and hold you over til next year."

To much and you will permanently bleach your roof, very noticeably if you use two different concentrations on a roof. Maximum liquid bleach mixture, approx 8 parts water to one bleach. Do not even think of using pool chlorine, it is to strong.

How I got rid of thick moss and slugs living under the shingles....

Purchased 5lbs of copper sulfate off Ebay, the cheapest per pound. There is only one quality for this purpose. Mix 1lb in 2 gallon of water, spray entire roof. Wait 3 weeks, hose down moss with a water water hose which remove most of the moss. Mix up another batch of the copper sulfate, spray it again. Let dry, mix up more bleach mix and spray; not only will the bleach kill the moss, it also causes the copper sulfate to deposit microscopic copper metal on the roof, which will keep the moss from coming back for years; it will not color the roof. Pure copper sulfate is cheap, if you buy mixes of copper sulfate from Home Depot they charge 30x times the cost. Also withe copper sulfate solution, wet the roof , do not let the solution sit in gutters, the aluminum will have a reaction with the copper sulfate. Wash out the gutters if you over apply the copper solution.

 

[Certified Drunk]

Tide laundry detergent, plus it will smell good.

 

[jkuro]

Clear out some of the trees.

 

[finn]

I think its zinc that's supposed to kill it.
Just spray it down with the green bleach house wash stuff.

Zinc for the win!

Somewher I saw zinc strips being marketed for just that purpose.

 

[Kpaige]

As mentioned zinc. There are various types out there what we used we put right under the bottom edge of top course of shingles and all the way across the roof we also put it about half way.

I like these instead of the tools it lays flatter.

 

[zak77]

I tried the zinc strips(3" exposure) and it worked but for only about 3-4' under them. I also used some Wet and Forget and that worked great. Highly recommended.

 

[Jackfre]

Several years ago visiting the architect who did our plans for our house and my shop we were looking over some work he was having done on his place. He brought me around the house to one roof section and it had heavy moss on most of the area but was clear below the flashed roof penetrations. Those flashings were galvanized metal.

 

[yatg]

Several years ago visiting the architect who did our plans for our house and my shop we were looking over some work he was having done on his place. He brought me around the house to one roof section and it had heavy moss on most of the area but was clear below the flashed roof penetrations. Those flashings were galvanized metal.

Because galvanized is a zinc coating. The zinc strips should be pure zinc.

 

[FL Guy]

"Sodium Hypochlorite will kill moss and hold you over til next year."

To much and you will permanently bleach your roof, very noticeably if you use two different concentrations on a roof. Maximum liquid bleach mixture, approx 8 parts water to one bleach. Do not even think of using pool chlorine, it is to strong.

This is so far from the truth.
First of all bleach will not “bleach” your roof. Can’t happen, no way. Bleach kills organic matter. It has no affect of petroleum products (shingles).
Look up ARMA for roof cleaning information.

 

[pcmeiners]

"First of all bleach will not “bleach” your roof. Can’t happen, no way. Bleach kills organic matter. It has no affect of petroleum products (shingles)."

First of all you have not experienced what I described obviously. I used a high concentration (5 water to 1 than 7 to 1) of bleach on my rear roof, in 2 different concentrations on a light brown roof in 2 different locations ( Certainteed roofing). 3 years latter I have a small but noticeable difference in color ; who said gravel colorant is natural. Thank you for your inexperienced opinion.

"Directions for mixing solutions of these ingredients may vary among shingle manufacturers and depend on the amount of discoloration. A typical solution should be one part chlorine bleach and one part water. Other cleaning chemicals or methods should not be used without approval of the shingle manufacturer."

One part bleach to one part water, and watch your colored roof change color dramatically from it original color; you will not like it.

 

[FL Guy]

"First of all bleach will not “bleach” your roof. Can’t happen, no way. Bleach kills organic matter. It has no affect of petroleum products (shingles)."

First of all you have not experienced what I described obviously. I used a high concentration (5 water to 1 than 7 to 1) of bleach on my rear roof, in 2 different concentrations on a light brown roof in 2 different locations ( Certainteed roofing). 3 years latter I have a small but noticeable difference in color ; who said gravel colorant is natural. Thank you for your inexperienced opinion.

"Directions for mixing solutions of these ingredients may vary among shingle manufacturers and depend on the amount of discoloration. A typical solution should be one part chlorine bleach and one part water. Other cleaning chemicals or methods should not be used without approval of the shingle manufacturer."

One part bleach to one part water, and watch your colored roof change color dramatically from it original color; you will not like it.

Then your shingles have variations from the factory and since your roof was so nasty, you didn’t notice it. Yet bleach doesn’t change the color or shingles.
My opinion is experienced just so you know. I’m sorry you don’t take care of your most prized asset, but hey, you keep thinking that you bleached your shingles

 

[coldh2o]

Spray it with some Wet and Forget. May take a few months but you should be good for a year or more.

Came here to say just this. Did mine three years ago and the moss has yet to return. Hard to say the Wet and Forget lasts that long - I had a few trees cut too - but it was definitely effective.

 

[marinusdees]

So our property has a lot of trees… a lot! So when we bought the place I had the owner pay to put metal roofing on the largest shed which is now my shop.
But the next one down, roughly 20x12 is still pretty old shingle. It’s also much shadier than this one so a constant battle is between me and moss.
I read a few years ago that copper can kill it. So I desheathed one wire out of a 12ga cable and fixed it to the peak. Now, like three years later I’m learning it’s bunk or the coppers not big enough.
I’m looking for passive ideas, something I can put up there and forget about until we reroof it next year.

Most cost effective for me. Tide WITH BLEACH. Sprinkle on the roof everywhere, light dusting works. The Tide holds the bleach in place while it works. Last time I did it was almost two years ago. I should do it again next spring. Never tried copper. Tried zinc strips. They killed moss for about two inched down from the zinc. So, if you put zinc strips every two inches, should work. I apply the Tide like feeding the chickens, doesn't have to be precise. Where I live, moss is a major problem. Tide with bleach is sold on Amazon. Sometimes hard to find in local stores.

 

[PoorUB]

Even 8 parts water to 1 part bleach is insane insane!

One ounce of bleach to a gallon of water will kill it just fine.

 

[skeer]

I did have a small spray bottle of dawn and bleach. No idea what the ratio is but it did jack squat.

 

[PoorUB]

You need to wash it off first, then bleach the roof. I would climb up and pressure wash the roof, using some care to not blast the shingles.

 

[like2wheel]

I mix 4 parts water to 1 part bleach to take care of the mildew stains on my house roof every year or so.
A couple years ago I had some left over, so I checked the roof on my shed in the woods & couldn't believe how bad the shingles were. All covered with moss & lumpy looking. Figured it was shot.
But I sprayed the bleach on anyway, & forgot about it. A few months later I remembered, & couldn't believe what I saw, the roof literally looked like it was brand new!

I would never scrub or pressure wash an asphalt roof. Just spray on bleach or Wet & Forget, & let nature take it's course.

 

[pcmeiners]

"Even 8 parts water to 1 part bleach is insane insane!"

When I purchased the house it came with the moss, I tried weak solutions of bleach it did little. As I stated I tried 5 to 1, was too strong, added more water, much better. Best to do an entire section at one time, do not do 1/2 a roof section, and do the other half the next day, that is how I ended up with a color difference.
ARMA recommends 1 to 1 solution, totally ridiculous. Use that much bleach and you will have very faded roof. If you have a white roof you have much more leeway, there is not colorant to fade.

"The Asphalt Roofing Manufacturers Association (ARMA) recommends using a 50/50 solution of household strength sodium hypochlorite (pool chlorine) and water to remove moss and algae."

If one has the time, copper sulfate solution sprayed a number of times over a few months is the safest and a long lasting solution to moss, zinc metal would be just as good.

"I did have a small spray bottle of dawn and bleach. No idea what the ratio is but it did jack squat."

Moss removal is warfare, you need a 2 gallon sprayer. Dawn or other detergents will de-grease. If it can clean oil from animals, it can remove some asphalt (oil based) from your roof depending on the concentration.