Gel wrote:
Moss Killer is now banned by powers that be' However Jeyes Fluid
sprayed on top, will kill it dead.
You'd need to scrape/hose off.

The 'professional' roof treatment companies use big mofo pressure washers to
clean it first. You would have to hire something with at least a 9hp diesel
or petrol engine to get enough welly to do the job properly.

--
Dave
The Medway Handyman
www.medwayhandyman.co.uk
01634 717930
07850 597257