The Brew Cabin

Posted: **Thu Feb 16, 2006 3:00 pm**

Hi,
I've recently had a 30sq.m patio laid in red riven concrete slabs. It was jointed by brushing in a mix of 5:1 and then struck. The joints look good but the patio has been stained by this process. How do I removed this residue and return the slabs to their original colour?

Posted: **Fri Feb 17, 2006 12:38 am**

Leave it to the weather - if you use an acid cleaner, you run the real risk of making it worse, as the acid is likely to recat with the red dye (an iron oxide) used to colour the flags.

You could 'accelerate' the weathering by plenty washing with soapy water and a stiff brush.

The Brew Cabin

Removing mortar stains from concrete slabs