grouting sandstone paver patio

[stevenbohrer]

Hi All,

Hoping for some input. I've installed about ~600sf of square cut, 1" thick, sandstone pavers around a pool... looks great. Now I'm grouting the installation. Have used a grout release product so it won't stick. Did a small section and am noticing white staining/streaks at the grout/stone intersection.

Does anyone know what this is? I think I heard somewhere where the lime from the original cement base can cause problems, is that what I'm seeing? Is there a way to get rid of it?

Thanks,

Steve

 

[bigeyes]

If you are creating this paver patio from concrete pavers, chances are you are noticing a byproduct of concrete called effloresence. If they are brick then it could effloresence being released from the concrete under the brick. I would use an effloresence cleaner first and if that doesn't work you might try muratic acid, just be sure to do a small test area first.

 

[mudmixer]

Sandstone is a sedimentary rock and can contain many materials depending on where it comes from.

How old is the concrete base?

Dick

 

[itsreallyconc]

you're laying pavers OVER the conc pool apron ? ? ? couple dabs of const adhesive to hold 'em in place IF NEEDED & apply mortar w/sock,,, if you've got an efflorescence problem you'll either need to replace the apron OR apply a vapor-impermeable barrier to it.

 

[subzero]

I think If they are brick then it could effloresence being released from the concrete under the brick...