Hi, I have a bit of a DIY challenge, our builder has painted the tiles on our balcony and stairs to the roof with a plastic waterproof coating, he has also painted the wall above the tiles (about 3 - 4 cms) with the same coating. 

I have used Disolvente to successfully remove the coating from the tiles and skirting tiles but unfortunately cannot get the coating removed from the marble render. It is only 3-4 cms but it looks dreadful, as it is dirty and sticky (because the product used was not fit for purpose as it melts in the heat!)

So far I have tried, Disolvente, Aguafuerte, Tile Renovator, Hot water, and a Karcher pressure washer; the pressure washer has had some effect but I think I need a chemical solution as well in order to avoid blasting off all the marble render.

Anyone had a similar problem or can offer any suggestions -

thanks

Rowantree

If you can get sodium hypochlorite - that might work.  Need to be really careful when using it and do not get onto skin or clothes.  Used in Ireland to get moss and such off patio areas.  Farmers would use it to clean out sheds.  It is much more effective than a power hose.  I really don't know where you would get it in Spain or indeed if you can.  I mentioned it to a friend at work and they said it's basically chlorine.  

 sodium hypoclorite is bleach available anywhere but i doubt is would work i think you may be thinking of sodium hydroxide a rather nesty substance which will remove most anything.

this is available certainly in mercadona and eroski.

beware it is nasty stuff and very dangerous in contact with water or aluminium.

WEAR GLOVES AND GOGGLES!!!!

Is there a spanish equivalent to Nitromors??

 How about using a small blow torch and scraper, then paint over where material removed.

Thanks for all the suggestions guys. I have tried Agua Fuerte which is Hydrocloric Acid and it didn't work, I tried Disolvente which is like a Nitromors/petrol based substance and it has worked on the tiles but not on the marble rendering. I can't use a blow torch and scraper on the marble render but have tried a wire brush and a scrubbing brush with Disolvente - this has had some effect but not enough to fully remove the coating :(:(:(:(  Suffice to say I am really fed up with the problem as nothing seems to be working.

Today I am going to brush all the marble render with Disolvente and then try the pressure washer - fingers crossed. If all else fails I think I will be painting over the marble render - Thanks again for the ideas and if you have any more please post them

xxx