Heavy staining by jointing compound - Staining from pavetuf jointing compound

[PaulR]

Hi, My building contractor has recently laid a nice honed, smooth, grey sandstone patio (40m2 - premiastone - Platinum - Natural Paving). All looked great until they came to point it using Pavetuf Jointing Compound. The contractor didnt read the instructions properly and used the compound dry. Now the stone is heavily stained along each joint line and has random marks, hand and foot prints on it. They have tried to clean it using Resin-Ex by Lithofin with a fine wet/dry sand paper and fine wirewool but its not made much of an improvment? The stain has penotrated 1mm or 2mm into the surface and i cant see a way of removing it. Any advice welcome please?

[KeburDave]

Unfortunately because Honed Sandstone is so porous once the Resin from the jointing compound has penetrated the surface of the stone it is almost impossible to remove the stain. We've tried everything in the past and to my knowledge there isn't much that can be done. We ended up having to take the whole patio up and relay porcelain. This has happened to us on two occasions now using Honed/smooth Sandstone, I will not touch the stuff unless it has been properly pre-sealed as it is just prone to staining. We even tried re-honing the slab and it never worked.

[PaulR]

Thanks Dave. The patio is basically knackered visually? Do you think it will become less obvious if i seal them? If the contractor was to relay the patio, they mentioned laying on top of the existing stone? Is that possible? Is that recommended?

[KeburDave]

We have tried putting an Intensifia on smooth Sandstone paving before but unfortunately it enhances the darker area's further, so although there normally is a slight improvement it is certainly not the ideal solution, I would be extremely concerned that your contractor has suggested relaying on top of the existing stone, there would be absolutely no benefit to you in this, all it would do is save him time and money but honed sandstone really needs a primer applied to the underside of the paving to help it adhere to the mortar bed so laying on top of already laid smooth sandstone is a definite no no, as well as damp course issues and levels etc

[PaulR]

Ive now tried all the products on the market to clean the stains but no joy. The only option now is to relay the patio. The conractor is a relative so im keen to help and be reasonable if i can. Can you suggest a stone/tile and method that could be used to correctley install over the top of the existing sandstone patio. Could it work if they are primed/adhered correctley? Would a vitrified porcelain tile work better in this situation? Any advice/help would be very welcome. Thank you.