We moved into a brick house not too long ago. There are a few areas that were renovated at some point and the mason did a poor job. It looks like some cement was put in after the bricks were laid and was smeared over the faces of the bricks. It's unsightly and doesn't match the adjacent areas where the work wasn't done. How can I clean this up?
dirty bricks on the left, clean older bricks on the right, beyond the railing.
There is a product called Sure Klean® that is used nowadays. I am sure there are other brands out there too. Muriatic acid used to be used, at least it was when I was a masons helper, but I think Its availability is regulated. Sure-Klean has it, just in small amounts I guess.
It needs to be diluted and protection worn, it pretty caustic stuff, so read the directions for use, and protect areas you do not want affected
If it is mortar marking (and it looks like it is), you should be able to get it off with brick acid (hydrochloric acid) and a wire brush. It's pretty nasty stuff though, so be sure to wear suitable safety equipment.
If the marking is efflorescence (salts coming out of the brickwork) brick acid won't always take that off the faces of the bricks.
