Would brick acid shift this

[steveo3002]

Had this up the side of the house as long as we lived here so since built in the 50s or proper long time , is this some thing brick acid would sort out ?

 

[MikeBs]

I had very similar at the front of my garage.
Brick acid moved some of it, brick acid and an angle grinder with a wire wheel moved most of it.
For the latter, just me sure you are well protected from any spray that occurs.
My house is built with “rustic bricks” which are contoured and made removing all of it tricky as there was a limit to how much pressure I was prepared to put on the wire wheel.

 

[voipio]

Pressure washing may well be able to shift some of it. Try using a pressure washer capable of 140Bar or higher.