On 24/12/2019 12:07, Chris Hogg wrote:
On Tue, 24 Dec 2019 11:38:30 +0000, Brian Reay wrote:

On 24/12/2019 10:27, Dan S. MacAbre wrote:
Mr Pounder Esquire wrote:
Bungalow, back end south facing. I was unhappily on the roof about 5
years
ago scrapping and brushing the moss off. The tiles are very rough and are
like steel.
I'd read that stringing a length of copper wire over the ridge kills
moss,
so I did it. The moss returned on the back end of the roof, never mind
and
******** to it, I'm not going up there again. Since Autumn chunks of moss
have been falling down almost every day. Maybe the copper wire takes
time to
work?


Ferrous Sulphate is my favourite for moss.Â* It is dead (but black and
unsightly) within a few hours.Â* But you'd have to somehow spray it all
over the roof.


Do you know if it is toxic when it gets into the soak away etc? I'm not
suggesting it is- I collect water from part of our roof to water the
garden etc.

No, in low concentrations such as you'd get in your water butt it's
not toxic to plants. In fact it's one of the chemicals recommended for
acidifying soil when wanting to grow lime-hating plants such as
rhododendrons, or for 'bluing' hydrangea flowers.


Excellent, thank you.