I've had moss spread on the north side of the roof - seems to be expanding each year. I was a little surprised this year on how much there is.

I have some kind of 100 year tile (concrete?) that basically forms a flush roof top. It's not wavy like many ceramic tile roofs.

Can I just buy something at HD and spray it up there? (although not sure about reach - it's probably a good 30' of coverage). I'm not comfortable walking on the tile - safety and I'd probably crack a lot of tiles.

I've heard that pressure washers are contraindicated for these tiles.

Hire some type of professional? Any idea who (what do I look for in the phone book)? Pet control? Gardener? Typical cost?

I have had some luck with straight white vinegar.

For the long term, you will want to remove it with some sort of cleaning agent and then seal it to prevent it from coming back. For the life of me I cannot remember the name of the chemical. However, I would start with your local concrete supplier, not Lowe's or Home Depot.

Zinc flashing is a common way to fight roof moss around here. Installed at the peak of the roof or between the roof and abutting wall for shed-type roofs.

Rain washes the zinc down the slope of the roof and kills the moss.

Moss is moss, I'm not aware of a reason why it wouldn't work on cement tile roofing.

quote:

Originally posted by PHPaul:
Zinc flashing is a common way to fight roof moss around here. Installed at the peak of the roof or between the roof and abutting wall for shed-type roofs.

Rain washes the zinc down the slope of the roof and kills the moss.

Moss is moss, I'm not aware of a reason why it wouldn't work on cement tile roofing.

Interesting. And it works? Typical cost? Contact a roofer?

jcasbolt: The cleaning agent - it's something particular for concrete that concrete suppliers carry? Or cleaning is something different and you're talking about some sort of concrete sealant after the moss is gone?

Have you thought of hiring a shaman to go out and shout "No mas"?

In certain parts of the world grass and moss roofs are the norm. Is there a problem with it or is it just and aesthetic thing?

I have had good luck with wet and forget.

https://www.amazon.com/Wet-For...emover/dp/B001GTRBMO

Just mix and saturate the moss. Takes a while but no damage to my roof.

quote:

Originally posted by PHPaul:
Zinc flashing is a common way to fight roof moss around here. Installed at the peak of the roof or between the roof and abutting wall for shed-type roofs.

Rain washes the zinc down the slope of the roof and kills the moss.

Moss is moss, I'm not aware of a reason why it wouldn't work on cement tile roofing.

I was thinking copper.Looks like they both work, along with lead.

https://www.thisoldhouse.com/h...oof-moss-zinc-strips

quote:

Originally posted by old rugged cross:
In certain parts of the world grass and moss roofs are the norm. Is there a problem with it or is it just and aesthetic thing?

Certainly a problem with shingles, it eats away at them and also slows the water flow causing leaks eventually. Getting mine taken care of is on the to do list soon, I’ll hire it out, not worth the fall risk to me on my 2 story.

I'll second the Wet and Forget. I haven't used my
power washer in two years since I found this.
It may take some time but eventually it works.
Have not used it on shingles but on aluminum siding, spray it on and in about a week, perfectly clean.

Baking soda - make a water solution? Or just dust dry onto the moss?

My dad got some powdered zinc from the paint store and mixed it with some water.

put it in a sprayer

agitated while spraying

the moss died and came off and hasn't returned in two years

quote:

Originally posted by konata88:
jcasbolt: The cleaning agent - it's something particular for concrete that concrete suppliers carry? Or cleaning is something different and you're talking about some sort of concrete sealant after the moss is gone?

Yes, believe both products are for concrete and masonry. We had a brick chimney repaired 10-15 years ago and that’s how it was done along with the masonry repairs. The guy told of me it was caustic c to asphalt shingles too. Check with the pros.

I get it in the north-facing valleys of my roof. I use a 50:50 solution of bleach and water and put it in my sprayer. Coat it all well and it'll die and turn black pretty quickly. Then I just get up there with a hose and spray it off.

quote:

Originally posted by Gustofer:
I get it in the north-facing valleys of my roof. I use a 50:50 solution of bleach and water and put it in my sprayer. Coat it all well and it'll die and turn black pretty quickly. Then I just get up there with a hose and spray it off.

I did about the same, but used a pressure washer to spray the moss, then after a few days back with the pressure washer which blew away all the dead and dying moss. Same mixture worked well for moss growing along the lawn as well. Just spray it around and let it work. Seems to support growth of new grass in the areas that had been taken over by the moss.

quote:

Originally posted by BigWhup:

quote:

Originally posted by PHPaul:
Zinc flashing is a common way to fight roof moss around here. Installed at the peak of the roof or between the roof and abutting wall for shed-type roofs.

Rain washes the zinc down the slope of the roof and kills the moss.

Moss is moss, I'm not aware of a reason why it wouldn't work on cement tile roofing.

I was thinking copper.Looks like they both work, along with lead.

https://www.thisoldhouse.com/h...oof-moss-zinc-strips

This is the simplest, most effective long term solution to algae and moss on a roof.

Wet and Forget is working nicely on my roof. A little moss and black... mold or something.

It's pricy. And aptly named. Don't expect to see any results. In fact it works so slow, unless you take "before and after" photos, you might not notice anything. I made the mistake of doing 3/4 of my back roof and now I can't make them match. lol It's a long slow process, but it works.

Doh!



I don't recall between which application this was... the first time I did it in the fall and didn't do a second dose till the end of the next summer. Point being, do the whole roof.

My BIL does this a lot, and he says Wash Safe Industries roof wash is the cats ass. Spray it on and leave it. Doesn't affect the lawn below either.

Was at Costco and they had Wet and Forget. Decent price so I picked it up.

Recommendations for a sprayer? Checking Solo, Chapin, Field King but none seem to go the distance. I’m guessing I need the spray to go about 30-40 feet. Maybe 50-60 if I want to hit my chimney (mildew?).

Or am I going to need to climb up onto the roof? In other words, hire someone?