Clearing algae on roof slates and patio area

Carnmore

Can anyone recommend a pour-over liquid to clear algae (no pressure washing)?
For a small roof and patio area.

neilmcl

Patio Magic is quite good but if you want the cheapest solution then just use a strong solution of bleach.

Mutton_Geoff

I use Moss Clear from Smart Seal. It's been very effective in sorting moss/algae on the roof and patio. Easily applied with a garden sprayer. No connection to the business, just a happy customer.

https://www.smartseal.co.uk/cleaning-products-accessories/moss-remover-moss-removal/

Alfrescodave

Can understand wanting to clean the patio but what is the thinking about cleaning roof slates?

Slinky

We tried Patio Magic and found it useless.

jimpwarsop

Jeyes fluid.

Apodemus

What is it that is growing on the roof?  Is it really algae or is it moss, or perhaps lichen?  The reason for asking is that while killing all three of these is easy, mosses and lichens will be more firmly attached and may need some form of mechanical action to remove them after killing.    Long term, a bare copper wire fixed along the top of the roof section may be sufficient to prevent recurrence.

Ajmason42

Pro kleen patio cleaner off amazon worked on our patio last spring  needs a good few dry days personally would wait till spring.  Ditto others about the roof  why are you wanting to do this?  Can you post a picture

Descrabled

I buy cheapest soap powder from supermarket and sprinkle over patio and drive in Spring. Kills moss and cleans without any effort.

Don't stint on the quantity of powder used. Rain water removes all the powder and dirt.