cleaning block paving

[sparklymarkly]

Our builders have left mortar remains/stains on our block paved drive. It was pressure washed by them when they finished the job. That was a few months ago and it looks like they had never cleaned it.
Any suggestions on how to clean it.

 

[WabbitPoo]

You can buy a mortar cleaning fluid from a builder's merchent (or from B&Q possibly). Its a strong acid which dissolves the alkaline mortar stains - you then wash it off. Works well but you may need several applications, and protect skin and eyes as it stings like the devil.

 

[Thermo]

as well as trying that get a spare block and use it to rub the surface of the other ones with

 

[megawatt]

I do this also and, if the stain is really bad, use sand between the blocks.