Moss on roof

[Woody2Shoes]

Moss is a northern thing, I am convinced as I never experienced it when living down south. We now use plain white vinegar, cheap as chips from Aldi and works a treat.

I would say it's a northern and southern thing (perhaps bigger differences east vs west?)! Where I live in Sussex is reputed to have a similar rainfall to Manchester. The primary drivers for moss/lichen growth are: air quality (i.e. rural not urban/suburban air pollution levels), and micro-climate - opportunitites for a section of roof to stay sufficiently damp between episodes of rain (being north-facing and/or under a tree makes an enormous difference).

 

[TheUnicorn]

Thanks all. I can't see much being done on this anytime soon. The tree has been trimmed back quite substantially so I will firstly see what affect the increased light and airflow has.

I hate ladders. I can put up with them a time or two a year to keep the gutters clear and I might get some hedgehogs to put up there to eat the moss.

you've misunderstood how a hedgehog works, they don't eat the moss, they roll around on the roof tiles until all the moss is stuck to their backs

 

[Jelly]

Most moss killing potions are pretty toxic - organic compunds with tin in them I think.
Having moss on your tiles may shorten their life a bit - holding moisture where it can freeze, causing spalling of tiles.
Having moss on your roof may shorten the life of any leadwork - the moss slightly acidifies rainwater which then corrodes any lead below.
I used a length of microbore copper tubing (useless for plumbing) clipped to the ridge - it soon weathers down so you can't see it and it emits copper salts that tend to kill the moss. Lead also does this - next time you see a roof with lead on, you'll spot the effect.

All that said, generally moss on a roof is not a big deal!

PS Moss is much more likely on north-facing slopes and/or under trees - removing the tree may be all that's required.

Whilst terrifying in their behaviour (including human reproductive toxicity, and changing the sex of marine life) I believe Stannanes (Organotin Compounds) have been regulated almost out of existence as antifouling agents, certainly they're banned for new maratime applications (where I could see a much stronger justification for their use than in domestic products) with isothioazolinone class compounds replacing them.

Certainly if those products are being marketed still ECHA (or the new HSE led UK equivalent), would probably like to be made aware of it.



For domestic use and use in cooling water circuits Iron Sulphates with iron phosphate or ammonium sulphate are now widespread as the predominant chemistry for moss killers, Ferromex being a good example.

Those preparations are not ecotoxic, or even particularly harmful to things other than moss although it would be unwise to get it in your eyes or have extended skin contact with them.

A big box of iron sulphate tablets and a cheap watering can both obtained from any decent garden centre would probably be a reasonable and cheap solution, albeit a bit faffy to apply.

 

[Selwyn]

Iron sulphate can stain.

Get a knapsack sprayer with an extension boom and try and apply benzalkonium chloride which is the active in the more expensive garden moss killers. Get it on ebay cheap and dilute it down.

I wouldn't pressure wash until you've done 3 sprays of this

 

[SammyQ]

Iron sulphate stain is a warm brown. What shade are your tiles Marcros? Would it blend in?

Sam

 

[Bm101]

Get out on the roof and walk about like a man Mark. If the slates are feeling a little slippery in the wet or damp a good tip is to stamp on them to create useful foot holds. You're welcome. Wear 70's shorts, spray yoghurt solution everywhere from one of those backpack sprayers. Yoghurt is great for killing moss. Probably best to also have patience.

 

[D_W]

Moss and such here in the states, we generally leave it alone other than perhaps to spray it with something that kills it. If it's already lifted anything as it grows, trying to get rid of it other than just stopping it is a good way to create problems.

 

[John Brown]

Moss and such here in the states, we generally leave it alone other than perhaps to spray it with something that kills it. If it's already lifted anything as it grows, trying to get rid of it other than just stopping it is a good way to create problems.

But don't a lot of houses over there have "shingles"? Most(?) houses over here have clay or concrete tiles, slates or stone, as far as I know.

 

[Amateur]

This is my solution.
I have the same problem.
I've researched and had companies out from roofers to professional countrywide roof moss removal companies.
On no account power wash.
It does degrade tile surfaces and makes them porous.
The roof moss must be scraped off. In between tiles too.
Then brushed.
Then a specialist moss killer applied...note....with a watering can. A spray isn't enough. It has to soak into the tiles and the moss.
A good company will show you other roofs they have done.
In my case I sat with a vicar discussing the church roof they had cleaned.
Again a decent company will put off the work until temperatures improve and the moss is actively growing. That's the time when moss killer will be absorbed.
Depending on your roof size scaffolding will have to be erected.
A good roofing company know that roof tiles, especially concrete Marley type tiles take up to 20 years to fully harden, and extra care is needed walking on the tiles.
So cost.
I've been quoted £700 to £1000 by different outfits. But it depends who you use. Keep away from the door to door, or small add amateurs.
Time to do the job between two to three days.
Two roofers.
All groundwork and paths sheeted up. Scaffolding erected. Gutters cleaned out after work completed and all moss disposed of from site.
I went with a professional roofer in the end that could give me third part references to follow up.
He gave me verbal 5 year but told us that he usually follows up with a moss killer every 4 to 5 years depending on how active moss spores have been in the area over that period.
It's not cheap.
But yet again a new roof would cost a lot more.

Good luck, whatever you decide.

 

[Owd Jockey]

I pressure washed the moss of my summer house roof using my 'cheapy' Nilfisk washer. The washer did not damage the felt roof tiles . The quickest and cheapest solution IMHO.

 

[Br5d]

Why not string a copper wire across the offending roof and that will kill off the moss. Job done.

 

[JAW911]

A local roofer scraped the moss off our roof. I then filled a couple of hand garden sprayers with ‘Wet and Forget’ (Google it) which is sprayed on and left. The moss didn’t return for two years after which it had a quick scrape again in places and it was sprayed again. Another two years comes to roughly today and I noticed just a bit of green staining now showing but no moss. spraying only needed which I will do in a day or two.

 

[D_W]

But don't a lot of houses over there have "shingles"? Most(?) houses over here have clay or concrete tiles, slates or stone, as far as I know.

There's a fair bit of tile and slate here, especially in some cities. New residential units are generally shingle.

There's an off and on interest in standing seam steel, but that's usually rural.

 

[Amateur]

I pressure washed the moss of my summer house roof using my 'cheapy' Nilfisk washer. The washer did not damage the felt roof tiles . The quickest and cheapest solution IMHO.

The original poster isn't talking about felt tiles.

 

[Spectric]

As I have said a light spray with vinegar (Acetic acid) and in a few days the moss is dead and its not toxic to the enviroment, just makes the area smell like a chip shop.

 

[MARK.B.]

Remove the moss and use to line and top off hanging baskets / use in planters - pot's etc , keeps the weed's down and help's when it get's dry , the moss stores a load of water and can save you time and effort when it come's to watering time. We have been using the stuff for years and over those years have saved a few bob on shop bought stuff. Every year i will get the request from SWMBO for more as the hanging baskets are done fresh each year. So out i go and harvest the latest crop from the workshop roof

 

[Stevekane]

However as your now talking about Felt we have a felted roof on my shed and on its east faceing side there is quite thick moss, it looks great and the birds do seem to like it but I did wonder if it might be eating into the mineral felt, is it likly to be damaging it?
Steve.

 

[francovendee]

In the west of France we get very hot summers and lots of moss on the roof.
I leave it for about 5 years and then scrape most of it off. I'd be tempted to leave it but lots of it dries up in the hot sun and falls, off blocking the gutters.
Standing on tiles you're likely to do more damage than the moss.

 

[Stuart Moffat]

Our village church had a similar problem with a north facing tiled roof. The architects recommended putting a copper tape along the ridge. The rain runoff then doing the rest. We also have overhead power in the village with bare copper strung along the road. Where that passes over roofs there is no moss underneath. I keep contemplating stripping a length of electric cable and trying it on my own garage roof, but haven't done that yet.

 

[Owd Jockey]

The original poster isn't talking about felt tiles.

Hmmm... I did actually read the original post and was quite aware of the context. I was simply relaying my experience of potential damage to the roofing material in response to one of Doug B's comments.