[drive surgeon]

hi i have been bust doing driveways and patios but i have been finding that where there have been piles of leaves they have left a horrible brown stain on flags, york stone etc. the pressure washer wont shift it. what can i use to get it out???

[drive surgeon]

anyonr had these stains before?/  like brown stuff.

[ace jetwash]

its most probably sap from the leaves, get some acidwash from jewson and give that a try or some strong detergent from a commercial supplier and a deck brush.
reseal afterwards to avoid this happening again.

[drive surgeon]

i wonder if roger oakley will know what to use??

[Roger Oakley]

It is most proberbly leaf tanin, very easy to get rid of.
What you need is Sodium Hypochlorite aka chlorine bleach, if you can get 13% or better, mix it down with water 1:1 when mixing remember water first then add the hypo. spray on to your surface, dwell time 20-30 mins then wash off. Watch out for your run off areas as this will kill grass, plants, etc. Just water any grass etc before you start. PPE, goggles, nitrile gloves, I also use a face mask (resperator type) This stuff will burn you if it goes on you so take care. I know so don't like the use of "bleach", but this will work for you.
Give me a call (during the day) Jamie if you are not sure about anything with this one.

[drive surgeon]

many thanks again rog, i was wondering if normal bleach would do it, but from experience i have found bleach can discolour white or grey flags so im always cautious.  where can you purchase this stuff from ( sodium hypochlorite )?

[Roger Oakley]

A swimming pool suppliers out-let.