New Patio marks and stains wont shift

[garash]

We spent quite a bit of money to lay a 24ft x 15ft patio area using Black
Slate. In all the ads they looked nice and equally clean almost with a sheen on them. Ours however look grubby all the time - except if it has been raining or if we hose it down. When it dries there are light patches and sandy patches which incidentally all vanish when we get the pressure washer on it! ???? We sealed
the patio after it had been laid. Is there anything else we could do to 'lock in '
the colour? If these were easy to dig up I'd get a Kango on them tomorrow, they are an eyesore and being such a big area they stand out.I am very disappointed with the final result. Also when we did the grouting we coloured the cement black - that has now faded to grey after we applied the sealant !

 

[r896neo]

these sound like mortar stains. did you keep it scrupulously clean as it was laid? Could also be a problem with the sealer.

mortar dye does not last.

how were they laid, what did you seal it with, when did you seal it?

Need photo's really, when dry obviously. a close up and a general wider view too.

 

[garash]

Thanks for your reply; We used the sealant supplied by the company who supplied the slabs and sealed it AFTER we cleaned up the slabs using a cement stain remover HP?? after which they appeared quite clean, and they were laid on a wet cement base. As they are very wet at the moment due to weather I will add some photos later today.

 

[r896neo]

what was the exact product and how long after laying did you seal it?

And a bit more info on the bedding please? I assume you mean a mortar base, what was the ratio of sand cement and what type of sand.

Also what were they pointed with?