Copper bars to stop moss

[Michael Chare]

Does anyone have any experience of using copper bars to stop moss?

I was thinking of laying a copper bar next to the ridge tile. If I do this what size bar would be suitable? Price suggests a thin one!

[Chris Hogg]

AIUI a length of bare copper wire will do, just so long as there's a bit of slow corrosion of the copper to wash down over the roof when it rains. Strip out some scrap 2.5mm T&E. Not sure how you'd hold it in place, but shouldn't be too difficult to arrange something.

[LumpHammer]

This sounds like it might be applicable to my house. Is it likely to be considered anti-social or polluting by anyone?

[Brian Gaff]

You surely need non tinned though don't you? I used to have some rolls of copper tape that wer meant fr this use, not idea how effective they were though, you cannot really prove a negative.

Brian

[Michael Chare]

I have found that I could buy 50mm wide by 0.6mm thick tape from ebay which could well be the cheapest option.

[Johny B Good]

Benjamin Franklin did. :-)

[Harry Bloomfield]

It happens that Michael Chare formulated :

What is needed is the largest surface area, for the lowest cost, consistent with doing the job. 2.5mm bare copper (not tinned) with two or three lightly twisted together, and mounted close to the ridge will do the job.

The idea is that the copper oxidises and the copper sulphate washes down the roof from the top, killing the moss on the way down. It works very effectively.

[Jethro_uk]

Where does the sulphur come from ?

[newshound]

Never heard of acid rain? It's the copper ion which is toxic, so carbonate / bicarbonate / hydroxide / chloride work just as well.

[Michael Chare]

Would 15mm copper piping as used for plumbing work?

[Huge]

Power stations.

[Michael Chare]

Or even 10mm?

[Harry Bloomfield]

Work, yes even even greater surface area, but being so light the wind might be a problem blowing it about.

[Johny B Good]

You do realise there is a risk that the species of Moss concerned might evolve a greater tolerance to copper poisoning if this practice becomes widespread?

It'll undoubtedly benefit the 'early adopters' for the first few decades but, after that, who knows?. However, I'd expect a newer and better solution will be available by then if that proves to be the case. :-)

[John Williamson]

If that was going to happen, it would have done so already, as copper roofs have been used for quite a few centuries.

[John Williamson]

And diesel cars and lorries, but not as much as it used to. Most, if not all, power stations have has stack scrubbers installed for a long while now to reduce sulphur emissions, too.

[Johny B Good]

That may be so but until recently, not by millions of buildings nationwide. In any case you're referring to roofs clad entirely in copper, not ones with a copper strip near or on the ridge tiles.

We may be about to "Perform The Critical Experiment", just as happened when GPs, especially in "Developing" countries, started to dish antibiotics out like 'sweeties'. Plus Maggie's forcing the NHS to 'contract out' cleaning services to private companies didn't help the situation in regard to the epeidemic of hospital bred 'Super Bugs'.

Although certain weed species have managed to colonise areas other plant species that would normally be expected to occuppy but for high levels of toxicity, there's usually more soil to absorb the toxic compounds into along with some level of 'washing' by direct precipitation so maybe not quite as toxic as in the case of a sloping roof endowed with a suitable copper strip. Also, of course, there'll be small islands of relatively less contaminated areas to give the plants a 'fighting chance' to develop higher tolerance levels to propogate further "into the Badlands".

You're probably right but I'm just saying that we should at least be prepared not to feign surprise if it ever does become a problem. Humanity has a history of underestimating Mother Nature's ability to 'outwit' us mere mortals.

[Johny B Good]

More specifically, Coal Burning Power stations.

[Tim Streater]

And volcanoes. I haven't looked up the figures to know whether they produce more or less than power stations.

[Jethro_uk]

Global warming fans are very unhappy when it's pointed out that *when* another Krakatoa, or Mt. St. Helens occurs, it'll undo all their hairshirt measures in a second.