Reflective staining

[Rickhend101]

So I laid a few Indian sandstone flags on dots and not on a full bed (rookie mistake) now I have reflective staining coming through, is this a complete loss and need to buy new stone or can it be lifted, cleaned and laid correctly to rectify??

Any knowledge on this subject would be greatly appreciated

[Jeremy Harris]

We also have Indian sandstone laid as paths and patios around our place, and the chap that laid it had previously been caught out, years before, when using the "Tommy Walsh" method, with dobs of mortar.  He went on at length about the need to lay slabs on a solid bed, and related tales of having to remove and relay some of his early work because of this problem.

 

I've had a look around, and sadly I've been unable to find any solid evidence to suggest that this staining can be removed.  The oracle on all that's paving suggests it's permanent: http://www.pavingexpert.com/stain_reflective_01.htm .  Not sure if anyone else here knows anything more. 

 

As the stone will have to be lifted, then you might want to try cleaning one or two slabs up, getting rid of any mortar on the backs and perhaps trying something like mortar cleaner to see if that will remove or reduce the staining.  Mortar cleaner is just dilute hydrochloric acid, so should dissolve any salts fairly easily, and it's unlikely to harm the slabs.  As you've really got nothing to lose, it seems to be worth trying.

[MrMagic]

As above, I had some paving laid and the chap did a full bed and on top of that used WOPC (white portland cement) 'just in case' to reduce any staining... this was on a light coloured paving.

 

Is there a place you can loose the stained flags? Under the bins / table / plant pots ?