Sandstone circle grouting

[boomish]

I just laid a sanstone circle -Mint fossile with two rows of Raj Green sets (blocks) around it, and I gota say what a great help this site is. I out in the 100 mm of foundation of scalpings then laid the slabs on a full motar bed of about 50mm+ trouble is this weather meant I couldnt grout it straight away.
I planned to use soft sand and some dye (liquid - Soverign chemicals Redtex) but after reading some more I wondered how best to do it and if I got the right dye, maybe I would be better off with one of these new ready mixed grouts?
A second problem which I hope isn't a disaster is I have found 3 of the slabs are loose, no one has really walked on them but I must have when laying the sets (I did cover it with a board) will the grout hold them together? the gaps are roughly 20mm with 25-35 mm depth
Thanks in advance for any tips..

[Tony McC]

If you;re not familiar with mortar pointing, then one of the modern epoxy or resin-based jointing products would be ideal.

And don't rely on jointing to fix loose flags: it never lasts. Much better to lift and re-lay the lose 'uns before you settle down to do the jointing.

[boomish]

Thanks for the reply Tony, well I'm a chippie so pretty good with my hands but no expert, I got a joint tool
ahh crap that means I'm gona have to chisel out the concrete underneth to fix the loose flags..

Cheers

Al

[Rich H]

Don't worry. Indian Sandstone is notoriously difficult to bond every single slab. Some of the lads here might not like this but IF (and I mean IF!) the bed set properly and the slab is not actually rocking you can clean the bed with a small brush to ensure there are no grit particles on the bed concerned then pour in a liberal amount of PVA. Pop the slab back in and it will almost certainly set in just fine. If it doesn't then don't hesitate to remove the area of bed concerned.

Just be careful not to whack out the adjacent slabs as well - it's better to use a disc cutter in my experience.

I think I'd better duck under the parapet now. :p

[hillandtrail]

I've used a slurry mix of cement and water beforeto fix loose slabs, got to make sure there is no grit under the slab though.

[Bilabonic]

I set a couple of loose ones with PVA and they are still fine 6 months later.....