Wet & Forget on roof

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Mike61

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#240377 5-Sep-2018 10:22

Just wondering if anyone has used it for getting lichen off a roof and how it worked out. Part of my color steel roof has a fair bit of lichen, tried my water blaster but it wouldn't touch some of it. Also my roof is reasonable steep so not keen on climbing over it.

Cheers

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#2084236 5-Sep-2018 10:49

Yep, should be fine.

We did our roof with either Wet and Forget or a 30-Seconds moss/lichen product.

Sprayed in onto the Lichen and left it.

After about 3 weeks, it was all gone, and it didn't come back (well at least for the three more years we owned the house).

Thinking about it a bit more - I'm pretty sure it wasn't Wet and Forget, because we bought it in Napier and I don't think they have (or at least they didn't then) a store there, so we would have bought it from Mitre10.

Also, on Wet and Forget products - off topic, but their Deck Cleaner is really good - did our decks last year and they pretty much came up as good as new (Kwila). I've since found out that the active ingredient is the same as Napisan (which is about a quarter or less the price).

SATTV

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#2084246 5-Sep-2018 11:09

If you listen to the wet and forget add's on the radio that is how they started by spraying peoples roofs and they would spill some on the driveway.

@Trig, thanks for the tip on Napisan, I will try that in a week or two.

John

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trig42

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#2084254 5-Sep-2018 11:20

SATTV:

If you listen to the wet and forget add's on the radio that is how they started by spraying peoples roofs and they would spill some on the driveway.

@Trig, thanks for the tip on Napisan, I will try that in a week or two.

John

Let me know how it goes. I haven't needed to do ours again since doing it with Hit The Deck, but have talked to someone that did his with both and couldn't tell the difference between HTD and Napisan.

Amosnz

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#2084272 5-Sep-2018 12:15

When we brought this house 8 or so years ago the decramastic tile roof had a lot of lichen buildup. We got someone from kowhai coatings to come and spray it, cost about $250ish back then (~240sq/m) from memory.

I was talking to him after and he calculated that at the concentrations he uses, we woulda needed about $1200 worth of 30seconds to get the same amount. Costs etc might have changed now, but just suggesting that if the whole roof needs doing it might be worth getting a pro in.

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frankv

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#2084274 5-Sep-2018 12:20

I used Wet & Forget (or maybe a clone, bought from Mitre 10) and it didn't do *anything* to the grey lichen stuff on my garage's Coloursteel roof. :(

qwertee

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#2084278 5-Sep-2018 12:30

Used wet and forget on a clay tiled roof. Took a few months for the yellow lichen growth to come off

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cruxis

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#2084289 5-Sep-2018 12:52

Make sure your drains have covers on, When the moss and lichen starts to fall off it can cause a blockage in the pipes in the next decent rainfall.

Mike61

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#2084304 5-Sep-2018 13:23

Thanks for all the replies. I'll let ya all know how it goes.

RunningMan

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#2084343 5-Sep-2018 14:09

frankv:

I used Wet & Forget (or maybe a clone, bought from Mitre 10) and it didn't do *anything* to the grey lichen stuff on my garage's Coloursteel roof. :(

Probably not Wet & Forget as I think they only sell direct.

tripper1000

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#2084348 5-Sep-2018 14:23

Just make sure you get the right product for moss and lichen.

There are cleaners that are chlorine based and anti-moss formulas that are Benzal-alkyldimethy (or similar) based.

I've found the stuff made for moss and lichen works heaps better and faster than the more general cleaning formula (funny old thing, but you never know because wet and forget is a brand not a product). Also I've found it to work better or porous surfaces like concrete than hard surfaces like steel but it did work on steel.

networkn

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#2084349 5-Sep-2018 14:24

frankv:

I used Wet & Forget (or maybe a clone, bought from Mitre 10) and it didn't do *anything* to the grey lichen stuff on my garage's Coloursteel roof. :(

I drove a Ferrari (or perhaps it was a Lada) around the race track, and I wasn't impressed at the performance.

A clone could have any ingredient. It's not a very useful as a sentence to assess the usefulness of the product :)

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tdgeek

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#2084355 5-Sep-2018 14:31

Try straight white vinegar, its great for moss. Its 5% Acetic Acid. I sprayed it at last house, bottom of wood fence palings, lawn border bricks, and left it. Disappeared. A lot of cleaning products have the same base active ingredients.

hairy1

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#2084432 5-Sep-2018 16:37

Either Wet and Forget or 30 Seconds work fine. Just make sure you don't fall off as it can be slippery.

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kryptonjohn

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#2084433 5-Sep-2018 16:38

Often wondered what the active ingredient of W&F is... that stuff is extremely expensive and I suspect the contents are only worth a few bucks... as is the case with the HTD deck cleaner.

[edit]

Duh! Google says it is Alkyl Dimethyl Benzyl Ammonium Chloride.

Fred99

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#2084476 5-Sep-2018 18:24

kryptonjohn:

Often wondered what the active ingredient of W&F is... that stuff is extremely expensive and I suspect the contents are only worth a few bucks... as is the case with the HTD deck cleaner.

[edit]

Duh! Google says it is Alkyl Dimethyl Benzyl Ammonium Chloride.

I've worked for a couple of companies who made the active ingredient. We sold it in 44 gallon drums, 1000 litre IBCs, bulk. Concentration was normally 50% w/w, it's a clear slightly viscous liquid at that strength. IIRC, price was about $2.50 / kg (10+ years ago though). I think you'll find that the retail product strength is more like 10%, so more like $0.50 a litre more or less cost (assuming that water to dilute it is free of course). The bottle it's packed in probably costs as much as the ingredients.

It's not quite as simple - there are some tricks - the alkyl group is from (natural) fatty acids, there's a range of carbon chain lengths / chain length distribution available commercially - and this has an effect on biocidal activity - some are more effective on lichen, algae etc, others more effective on bacteria (it's the active ingredient in most household disinfectant).

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