In article ,
"Muddymike" writes:
|
| Yes Nick it does scrape off when I can get to it, but up on the roof its not
| that easy. Does it do any harm on roof tiles? Bob the cross eyed builder
| says it eats the concrete tiles away, but does it? I would be just as happy
| to leave it where it is if it does no harm.

You should live so long!

There are tiles (admittedly 'brick' not concrete) that have had moss on
for several centuries. Its causes some damage by trapping water, which
dissolves the concrete, but we are still talking about MANY decades and
perhaps a few centuries.

| The paths it covers do become
| quite slippery, I have scraped it off but it returns quite quickly which is
| why I would like a chemical solution.

Compared with algae, I find moss positively grippy :-( Many of us have
that problem, and none of us have a solution. Sorry.


Regards,
Nick Maclaren.