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Posted: Fri Jul 25, 2008 6:49 am
by wein1
i am starting a 9m sq patio with crazy-paving red/orange jerusalem limestone. the pieces range from 10x10cm to 1/2m sq. thickness varies from 2-5 cm
i read in the main webpage that placing them on a 1:10 cement to sand base is best

my question is: how much water should one put onto this cementitious base before setting the stones? in particular given this cement-sand base is 50mm thick?

simon

Posted: Sun Jul 27, 2008 7:15 pm
by Tony McC
I have a sneaking feeling that the Jerusalem limestone is one of those tricksy blighters that needs to be handled with kid gloves to avoid wicking cement to the surface. I know there's a very similar limestone that hails from Crete/Cyprus (can't recall which) that needs to be laid on a white cement mortar and slurry sealed on the underside prior to laying, otherwise it is ridiculously prone to picture framing and bed staining. At only 10-20mm thickness, this paving of yours would have me worried.

In view of the above, I'd probably use a pre-placed concrete slab, 75mm thick, and then use either a thin-set mortar or an SBR-enhanced mortar to fix the pieces in place, once they been sealed using a cement/SBR or cement/PVA slurry on the base. If I had to lay them directly onto a laying course, I'd use 50-75mm of the aforementioned SBR mortar, but would be wary of just how damned fast that stuff will go off, especially at this time of year.

Posted: Mon Jul 28, 2008 7:46 pm
by wein1
thnak you - in fact the stone is 20-50mm thick - when you mention mortar/svp slurry does this mean that the stones are laid onto a wet mixture - that is, the 1:10 cement:sand plus SVP base for the stones should be quite wet


simon