[James pryer]

Hi all,

I’ve manage to scrape the worse off a roof. I’ve then proceed to wash with a 4.5% hypo mix. There was still patches of remaining moss left. Will some of this drop of?
What’s the best time to leave hypo mix on the roof for?
Will giving it another hypo spray do much more cleaning or not worth the extra cost?
What are people’s best attitude towards spray hypo? Do you prefer to spray a strong mix then a weak mix or the other way round?

Many thanks,
Stay safe.
James

[Smudger]

If using Hypo or any other 'soft wash' chemical you really need to remove all the moss - these chemicals really don't have the grunt to dislodge growing moss - it might turn it white, some may dye, but falling off takes a long time and IMO is reliant that you  have a long period of dry weather followed by really heavy rainfall to wash it all off ( then blocking the gutters  )

Darran

[Mike Halliday]

Does hypo kill moss? And at what dilution?

I have my doubts, it might discolour it but as for killing it I’ve never seen any technical data that suggests it can be used that way

[Splash & dash]

Does hypo kill moss? And at what dilution?

I have my doubts, it might discolour it but as for killing it I’ve never seen any technical data that suggests it can be used that way

I don’t  have any scientific proof  but yes it does  kill it we have done  quite a few roofs by scraping them first then applying a 4-1 hypo mix the roofs that we have done are totaly clear of all moss , licken ,silver, black,red,orange it took around 8 months in total ti get this result but there has been no re growth at all in over 3 years . I have done  other roofs the same way using biocides and again have achieved similar results but material costs are 10x  higher using bio