[Denise l]

Part of a builders clean I have been asked to clean is external black polished  block brickwork which has white render on it. Any advice on what to use please?Its a new build.

thanks Denise

[Kev Martin]

Do a small acid test first5 to make sure it is not acid sensitive.  A drop of jif lemon juice or vinegar will do in an inconspicuous area.  Then once you are sure try Aqua Mix Phosphoric Acid Substitute Diluted to remove.  If that fails the render may be polymer modified so you will need Aqua Mix Sealing and Coating remover first to break down the polymers then the Phosphoric Acid Diluted.  If it is Acid sensitive come back to me and iwill give you another solution

Kev Martin
Marble Life Ltd

[Denise l]

Thanks Kevin, youre a minefield of information. Denise

[Denise l]

Kevin, Apparently this render is a Marmorit product for Noblo. Its a marble based textured render made of dry mortar with lime.cementious binder, water repellent, vapour permeable and weather resistant. The chaps who applied it have let it go all on the black polished brick. Its really bad. What do you suggest using to get it off please?
I have an Acid 80 wash but would like your advice 1st.
Thanks

Denise