Advice on sandstone staining. Reflective? Photos added

[catseyes]

Hi everyone. We had a gorgeous smooth grey sandstone patio put in 2 months ago now. We started getting white marks on some of the slabs.
Had the contractor back.. it’s salt it will fade or you can use a salt remover.. you can see the salt coming up through the mortar ridges underneath.

Ok so took his word for it, on doing more research it seems that it’s not salt but reflective staining. Every slab looks a mess
What the hell can I do with this? So much money to look awful.

[catseyes]

https://www.flickr.com/photos/165794421 ... res/3sL253

https://www.flickr.com/photos/165794421 ... res/VF8300

[liamb2001]

i can sympathise with you on this. In march last year we had a builder lay some stones for us. We noticed some unsightly stains appearing when he was doing our lower garden. I read on here what reflective staining was and pull him about it he claimed initially they were a full mortar bed, i pulled one up and it was dot and dab (he also used pva ), when i quizzed him he said dot and dab or doing the edge was fine on indian stone, didnt even care id caught him lying!

He came round and ripped them all up and the stains dissapeared from the stones, he then claimed relaying them would fix the stains despite us reading on paving expert it wouldnt. he relayed them at no extra cost and within a week the stains came back.We ended up threatning him with legal and found another builder but a harsh lesson learnt.

Your stones look really nice but those do look like reflective stains to me (i hope im wrong), my advice would be to take one up yourself and assuming there is cavaties underneath it take a photo and tell him hes not laid them properly (the briitsh standard / legislation can be found on this website) and its damanged the stones and that he needs to lift them all up, buy new ones and lay them at his own cost or pay for someone else to do so, they should be coated with SBR/slurry usually as well to stop the reflective staining and keep them stuck down.

[Bilabonic]

What is reflective staining?

A builder i know lays LOT of stone like this and has always used PVA on a full bed and never had problems?

Can someone explain please as he is about to do mine in Grey/PVA rears and full bed.

The Forum seems to 'dead' from when i came on here years ago as well!!

Thanks

[digerjones]

The sbr forms a bond bridge. The recognized method is a cement slurry with sbr painted on back of flags. Pva is not frost proof