Moss on Shingled Roof

[stevej37]

It started a couple years ago and now it's getting worse. On the north side of the upper story roof, where the roof pitch is too much for me to take a chance, the small green lines on the shingles have turned into round grayish/green 'barnacles'

The shingles are less than 20 years old, but the sun never dries out the north side because of the pitch.

Saw a sign stuck in the ground on my road that said 'Roof Cleaning' and a phone #
Called him and he came out this am. and gave me an estimate.
He will be here Wed to spray the entire roof with Sodium Hypochloride Concentrate.

I hope it works.

[masraum]

Is the moss a problem?

[stevej37]

Originally Posted by masraum

Is the moss a problem?

Yes, it roots itself into the shingles and grows. I tried spraying what I could reach with bleach and water blend last year, but about half of that area was unreachable. I used a two gal pump sprayer and it wouldn't go far enough.
He said he will use a truck mounted pump with a long hose and do it himself. He said he will be able to walk that higher pitched roof that is the worst.

I'm not scared of climbing up there, but sliding down to the 10ft fall to the ground is not good.

[Crowbob]

Were those shingles ever stained or treated with preservative?

[HobieMarty]

Sounds like a soft wash is in order, or try to spray some moss killer/algae killer/bleach solution in the area and kill the stuff.

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[stevej37]

They are asphalt shingles (I think that is the name for them) black and less than 20 years old...good shape. (3 tab shingles)

Soft wash is what he said he does...he never uses a power washer on shingles. Just soaks them down and it takes a few days before it dies. Then nature will take care of what remains...he said. (wind and rain)

[masraum]

Originally Posted by stevej37

Yes, it roots itself into the shingles and grows. I tried spraying what I could reach with bleach and water blend last year, but about half of that area was unreachable. I used a two gal pump sprayer and it wouldn't go far enough.
He said he will use a truck mounted pump with a long hose and do it himself. He said he will be able to walk that higher pitched roof that is the worst.

I'm not scared of climbing up there, but sliding down to the 10ft fall to the ground is not good.

So it's ugly or it actually harms the shingles?

I get it. I'm not afraid of getting on our second story roof. I've been up there. But the pitch is higher than most houses around here, and the idea of sliding off the second floor is "exciting", but not in a good way.

[stevej37]

Originally Posted by masraum

So it's ugly or it actually harms the shingles?

I get it. I'm not afraid of getting on our second story roof. I've been up there. But the pitch is higher than most houses around here, and the idea of sliding off the second floor is "exciting", but not in a good way.

I don't think it 'harms' the shingle so much as it stops the ability of the roof to shed leaves, twigs, rain and dirt. The moss makes like a small dam and doesn't shed.
Plus...it is ugly.

Part of my problem is that I have a mature hard maple tree that shades part of the roof. That just increase moss growth. I'm working on trimming some upper limbs of it. I need to refresh my tree climbing skills.

.

[flatbutt]

Originally Posted by stevej37

They are asphalt shingles (I think that is the name for them) black and less than 20 years old...good shape. (3 in 1 shingles)

Soft wash is what he said he does...he never uses a power washer on shingles. Just soaks them down and it takes a few days before it dies. Then nature will take care of what remains...he said. (wind and rain)

Soft wash ok but he's using bleach.

[stevej37]

Originally Posted by flatbutt

Soft wash ok but he's using bleach.

Reading his emailed estimate.....6% Sodium Hypochloride concentrate....which I think is another name for bleach.
I used it before for the same reason and it works. I just couldn't get it in the spots where it needed it the most. The roof pitch is too much.

[Bill Douglas]

Professional moss and mould killers work well. It's sprayed on and appears to do nothing, then a few months later it's died and fallen off. It's important to not water blast the mould off as the spores just grow again. A chemist friend told me it's the "salts" that kill the moss and ordinary bleach won't kill it off long term.

[stevej37]

Originally Posted by Bill Douglas

Professional moss and mould killers work well. It's sprayed on and appears to do nothing, then a few months later it's died and fallen off. It's important to not water blast the mould off as the spores just grow again. A chemist friend told me it's the "salts" that kill the moss and ordinary bleach won't kill it off long term.

That's how he described it to me also. He said they would cover all the shrubs and bushes around the house because they could be killed from the solution.

I thought he said it would work after a few weeks...either way is ok with me.

.

[Bugsinrugs]

Insurance company flew a drone over one of my rentals and threatened to cancel us because we have moss on the asphalt shingles. Since the roof was over 20 years old we decided to replace it. Insurance was happy and reinstated our coverage. The following year the insurance company cancelled us. Their excuse was that they are not covering homes in California any longer.

[Por_sha911]

Bugs: so why don't you take the hint and get out before things get worse?

[stevej37]

Wow!....I hope you found a better insurance company after that.

[dad911]

Originally Posted by stevej37

Yes, it roots itself into the shingles and grows. I tried spraying what I could reach with bleach and water blend last year, but about half of that area was unreachable. I used a two gal pump sprayer and it wouldn't go far enough.
He said he will use a truck mounted pump with a long hose and do it himself. He said he will be able to walk that higher pitched roof that is the worst.

I'm not scared of climbing up there, but sliding down to the 10ft fall to the ground is not good.

I can reach the peaks of my roofs with a Bauer (harbor freight) 20v chemical sprayer.

[HobieMarty]

Moss and microbial bacteria will eat away at the shingles. Not only does the presence of such things detract from the overall appearance, it actually will weaken and eventually destroy the shingle.

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[stevej37]

Originally Posted by dad911

I can reach the peaks of my roofs with a Bauer (harbor freight) 20v chemical sprayer.

I have the same Bauer sprayer....I use it often for spot weed spraying in my lawn.
My roof has two pitches/angles....the first (less angle) I can walk around w/sprayer.
The other pitch (more angle) I can't without sliding down. The Bauer sprayer wouldn't reach up another 10-15 feet. And then there are the dormers to block any spraying from below.

Plus...if I do slide down to the long fall...I have river rock around the base of my home instead of mulch.

[A930Rocket]

What about an electric pressure washer with a siphon, that you can use yourself?

Also, can’t you install a zinc or copper or ? strip up high to to keep the shingles from growing barnacles, etc.

I don’t mind going up on high roofs, it’s the sudden deceleration I don’t like.

[SpyderMike]

I use baking soda. Sprinkling a line of it at the peak. The next rain spreads it down. That changes the chemistry and kills the moss. After it's dead I go scrape it off with a plastic scraper.