How to remove cement dropped on block pavins

[PFMills]

The painting contractor workers were careless and didn’t cover the block paving before working above with cement, so now have cement droppings on the blocks.

 

Contractor says I can get that off… not my experience without leaving marks behind.  Anyone know any product that can remove the marks left behind after scraping the blobs off and blocks still look ok.

[Dante99]

10 minutes ago, PFMills said:

Contractor says I can get that off…

So tell him to do it, he is responsible for the problem.

 

Depends on the block surface but you are right that it is often not possible.  Also depends on how long the cement has dried.

 

Someone way back said vinegar but that was about a roofing tile.  Might try a spot out of the way.

[Crossy]

Yup ^^^, that would be my response too, he made the mess, he can clean it up or replace the pavers.

 

In reality neither is going to happen ???? 

 

EDIT A thought, are the pavers symetrical, could you just turn them over?

[PFMills]

9 hours ago, Crossy said:

Yup ^^^, that would be my response too, he made the mess, he can clean it up or replace the pavers.

 

In reality neither is going to happen ???? 

 

EDIT A thought, are the pavers symetrical, could you just turn them over?

No, one side only blocks, Could be some discussion when final payment time comes.

[sometimewoodworker]

hydrochloric acid (muriatic) or phosphoric acid are the go to cleaning agents. Though they are extremely dangerous too use and if not correctly neutralised will continue to do nasty things to the surrounding area.

[PFMills]

2 hours ago, sometimewoodworker said:

hydrochloric acid (muriatic) or phosphoric acid are the go to cleaning agents. Though they are extremely dangerous too use and if not correctly neutralised will continue to do nasty things to the surrounding area.

Ah… I have some, I did think about using that. 
 

I bought it when I was repairing whatever you call the ‘small colored stones set in concrete’. Dilution is 10:1.. use it to remove just a small layer of cement.

 

Goggles, gloves and at least jeans to be worn. And of course add water to the acid.

[treetops]

Can they be swapped for ones in a less conspicuous area?

[sometimewoodworker]

3 hours ago, PFMills said:

Ah… I have some, I did think about using that. 
 

I bought it when I was repairing whatever you call the ‘small colored stones set in concrete’. Dilution is 10:1.. use it to remove just a small layer of cement.

 

Goggles, gloves and at least jeans to be worn. And of course add water to the acid.

Don’t forget the wellies and an ample supply of baking soda just in case.