Advice on cleaning patio slabs pls

Hi 

Just pressure washing some patio slabs for a window cleaning customer.

Should I use a degreaser to get black spots off or will that melt the stone/bricks? 

Thanks for advice.

James 

The black spots are litchen and degreaser won't affect them as they're organic and not grease based. I believe hypo or such may be required to further remove them.

Sent using the Window Cleaning Forums mobile app

Thanks 

So not Ubik then?

Jago said:

So not Ubik then?

Click to expand...

Virosol, Ubisoft, and screwfix degreasers are used to remove algy or general road grime from glass or plastic they aren’t suitable for removing things from concrete 

No you you need to use a biocide and leave it a few weeks to work or use a hypo mix let it dwell for 45 muinits then pressurewash should all come off 

After you have pressure washed the patio, you could buy a bottle of bleach and scrub it in if you don't have hypo. Then leave it for 40mins and pressure wash off. Reapply to stubborn stains with more bleach and scrub and leave on for 40mins and pressure wash off. Its a short term fix till you know where to buy your hypo from.

Great thanks 

?