Hi,

It seems that "brick cleaner" or "brick acid" is what I need to clean mortar
splashes from the brickwork on the outside of my house. Just to be clear,
there are not actual lumps of mortar, just the staining from where mortar
has been.

Anyway, look all over B&Q and couldnt find any "brick cleaner".. the old boy
who works there showed me where all the cleaning stuff is, and apparently
they dont sell such a thing (?!)

He suggested Caustic Soda instead. Now, I know this is ideal for cleaning
drains, but what abour mortar stains from bricks? I got some just in case
(it's not expensive, and i'll use it for other things anyway).

Can I use this? If so, what sort of strength/dilution should I use?

Cheers
Chris