Smooth kandla grey large grease stains - Drainage leak

[Freddy871]

Without me knowing drain for sink/dishwasher/bath waste had overflowed due to blockage. Not sure how long it had been leaking i noticed but must have been some time as has left huge oily stain slick across a large part of patio. I tried a small area with washing machine liquid and scrubber, no joy, then a diluted Sodium Hyperchlorite, scrubbed again, made a small improvement but nowhere as much as required. Am i fighting a losing battle or any other cleaning agents tip hints tricks . It only been down a year I am so gutted. Link to pics below showing area tried and overall how bad it looks.



Stained kandla Honed

[RAPressureWashing]

There are a couple of products that would work, has the paving been sealed ?

[Freddy871]

There are a couple of products that would work, has the paving been sealed ?

Hi R&A . So spent some time today in an attempt to remove the obvious fat/grease slick from the surface to see how bad beneath. Wrongly or Rightly, had some washing machine detergent so let that sit in a slurry for 3 hours without drying out, By the time I had finished jetting the whole patio it was difficult to see as the kandla looks totally different when wet. That said does look a lot better. we will see when dry tomorrow. I never sealed the slabs when laid 12 months go, but here's the caveat. To my peril, I used "Nexus ProJoint V75-WT 2-Part Epoxy Resin Mortar" for joints that left a residue over most of the patio (awful stuff and spoilt the overall finish IMO). The residue did seem to have dispersed over summer last year but not sure if it had any sealing effect . I will post some fresh images in the morning, but feel it will need more attention. So any products you know have you have that can permeate into the stone would be fantastic. Images in link below of how it looks now, a little better, but not good.

After cleaning with detergent

[RAPressureWashing]

Ah right, so resin mortar hazing !!! Couple of products you can use/try, Tavec 201 from Tensid UK Ltd, or Lithofins Wax Off.
The Tavec 201 would be my choice as it's a sealing & coatings remover and does (I've used it many times) remove some maybe not all resin hazing, the Wax Off can also remove the hazing but the Tavec is the one I'd go for first. What you also have is the greasy residue is stuck to the hazing stupid as it sounds, again the Tavec will cut through this. Both the above products are natural stone safe, both are easy to use, just take your time and read in instructions etc and follow them. If you have access to heat, as in a hot/steam pressure washer this will help, but cold will work just might take longer.

[Freddy871]

R&A, superb, and many thanks for your tie on this.. as mentioned good old soap detergent did a good job on top surface , but the fat/grease stain is staring me in the eye., and it aint a pretty sight.. will do some shopping over weekend on the products mentioned. Results to come. Is it worth the effort to hire a steam/hot water cleaner? what you think.? Also since the jetwash/detergent the surface feel squeaky clean so staining seems to be within the limestone .. presume the 201 product you mention will penetrate to remove it .. just trying to make sure i have best chance of sucess..

[RAPressureWashing]

You can do these type of stain removal/cleans with cold, heat does help, but not a must have, with the 201 dwell time is the biggest factor, it can be 1 hour? it can 3 hours or more, yes it will penetrate over time, the thing is, don't let the 201 dry out, we apply it, then if it's a really warm or hot day cover with polythene etc, if it looks like it is dry just apply some more, it goes on quite thick anyway.
Lithofins Wax Off you should be able to get from a decent Tiling store or extensive.co.uk or it might be .com? As for the Tavec 201, you'll only get this from Tensid UK Ltd, it's not a shop or internet purchase, if you google their website, you'll need to give them a call to order etc.