Maintenance question - sandstone

Rick · Post: # 97796Post **Rick** Tue Apr 29, 2014 1:24 pm

This is a maintenance question for those that might know ...
I have large Indian sandstone patio and it has (in very short time) gone very grotty.
I am about to re-point it (separate thread) .... after pressure washing, it still has a lot of black staining ..

Any products you can recommend to clean these, might as well do this prior to pointing.
Are there chemical cleaners, bleach etc?

Sample pic ... just pressure washed:

RAPressureWashing · Tue Apr 29, 2014 9:55 pm

One of my cleaning mixes/solutions is on the stain removals page, this will get rid of the lichen spots/marks.

Post: # 97835Post **Tony McC** Wed Apr 30, 2014 12:49 pm

....and here's a link for that page.

Rick · Post: # 97842Post **Rick** Wed Apr 30, 2014 1:08 pm

R&A Pressure Washing wrote:One of my cleaning mixes/solutions is on the stain removals page, this will get rid of the lichen spots/marks.

.
Is this the Sodium Hypochlorite (NaClO) at 13-15% mixed 3:1 plus shampoo recipe ?

That will clear the black spotting reaming after pressure washing ?

r896neo · Post: # 97863Post **r896neo** Wed Apr 30, 2014 7:16 pm

yep i have used it very effectively on lichen spots.

Chemical treatments will also keep the grime away for longer than pressure washing in my experience.

Rick · Post: # 97864Post **Rick** Wed Apr 30, 2014 7:18 pm

Thnx ... I'll get the gubbins in to make it up.

RAPressureWashing · Wed Apr 30, 2014 8:44 pm

Rick wrote:Thnx ... I'll get the gubbins in to make it up.

Just follow the instructions on the site to the letter and you shouldn't go wrong, any problems just post on here or email me.
Roger