Preventing discoloration of light sandstone

[thetourist]

I will be laying some Pavestone Sahara slabs in the near future, and I'm concerned about the issues raised on Tony's page regarding light coloured slabs being discoloured by materials in the bedding mortar.

I assume that the slabs I've linked to would be considered light enough for this to be an issue?

What I would like to know is - does the use of a cement-SBR bond bridge also prevent discolouration as well as aid adhesion? In that it creates a seal on the underside?

I noticed on the Pavestone site it reads:

Pavestone strongly recommends sealing the underside of natural stone paving prior to laying with a PVA sealant. This will deter the possibility of surface staining on the flag face which can be caused by the drawing up of salts from the cement through more porous stone such as Fossil.

Ideally, I would like to avoid having to buy silver sand & white cement as this will significantly increase the cost of the project.

I'd really appreciate any advice.

Thanks in advance.

[rimexboy]

SBR does help with that as well,

some even paint the back of the slab with it to..

[lutonlagerlout]

i find with any hand cut sandstone there is no issue
it only seems to occur on machine finished stone
obviously you need a full bed under each flag
the honed and flamed stone seems more susceptible to patching and efflorescence
why? who knows
LLL

[thetourist]

Thanks for the comments guys. I feel confident that it wont be an issue then, particularly if I go ahead and use the bond bridge.