Is this efflorescence and do I remove it before or after?

[Sprogginz]

I've just had some paving blocks but they have this on them. I think they've been in the builders yard for some time and I don't know if this is acceptable or normal. Should I complain?



Should I remove this stuff before or after I've done the job and how to do you remove it?

I'm actually using them as a mowing strip so they will be flush with the lawn. If chemicals are needed then I'm assuming they'll have be done before.

Thanks very much.

 

[Sprogginz]

Just realised, I think they're all like this. Certainly not the same state as the ones used last year to install the patio.
They've also got some very slight moss (or something green) on them.

I guess the first (perhaps only) question to actually ask is, If these were delivered for a customer of yours, would you accept them?

I really don't want to come across as a moaner or fussy, but if I put these down, they will look different from the ones already down yet they're from the same range. My weekend plan has now gone to pot. I think either this project or I am cursed as this isn't the only issue.

Hope you can help.

 

[bobsuerita]

thats the underside of the block

 

[Sprogginz]

thats the underside of the block

Yes, but it's same condition on other side.
Thanks.