Oversized rough hewn flags - Tips for laying very heavy uneven limest

[Mosquito]

I have had to lift 50% of the mixed slate and limestone slabs on my patio to re-lay drains. Some are up to a metre square and 150mm thick with irregular (substantially lumpy) undersides. Some can only just be moved (on edge) by two people - possibly up to 100kg each?. A mix giving maximum ease of height/level adjustment would be desirable to avoid too much re-lifting (and acupuncture/physio).

Any tips on how to handle these, and what bedding to use would be appreciated. I am looking to point these to minimise water penetration as the patio is laid on retained ground at first floor level. Surface water will be managed by fall to a channel drain.

Many thanks.

[sy76uk]

You'll need a stiff mix and you'll need to judge the amount of bedding needed well to a void having to lift them and adjust the bedding layer.
A trick I use to lay flags the size you described is to use the thin plastic straps you'll find on a pack of pavers and lift the flag into place the same way you'd lift a coffin then you can pull the straps out without disturbing it to much.

[Mosquito]

Thanks for that sy76uk, I will give that a trial on one of the stones. I have to admit that I had been considering hiring (or lashing up) a tripod crane and a hoist and not really considered trying to lift them off the ground manually, but you have got me wondering if it would be possible for many of them.

The thing is, there are a few that I am pretty certain are too heavy to do that under any sort of realistic control (two of us struggled to 'walk' them a few feet); a hoist might even give us the slack to re-level and re-distribute the mortar as we lower a stone into its mortar bed.

I am just now baulking slightly at the idea of preparing a mortar bed underneath a danglng quarter-ton slab... Hire costs look to be in the £100.00 region; what does anyone think?

[London Stone Paving]

Sounds like a challenging job.
Would be very interested to see some pictures of the stone
How flat are the surfaces of the stones? May be possible to use a vaccum slab lifter. It would be easier to use than a sling and hoist.