Lifting huge stone flag....

[2987fr]

Those don?t have to put it back on the new mortar.

A forklift will get it out, its putting it back that?s the harder part.

[The Natural Philosopher]

Mmm. yes. I think your calcs are OK

This is levers and fulcrums time. or a crane or digger

[alan_m]

Level up each edge - insert 50mm supporting blocks at each corner and check levels.

Pack in some fairly dry mortar very tightly using a short plank to push it in. Lever up slab again to remove spacer block. Check for level and fill the gaps left by the spacer blocks with more mortar.

Make sure that you don't bridge your damp proof course where the slab meets your wall.

[spuorgelgoog]

There is the option for presumably a crane for repeated use, but if you watch the video two blokes handle a slab quite easily. The vacuum part is battery powered.

Owain

[rmlaws54]

Could you use four car jacks, one at each corner, placed in holes dug inderneath. Raise it up, push in mortar etc (keepinng away from jacks) then lower the jacks to get the required position and allow mortar to set. Then remove jacks.

Or, use levers to wedge it at the required position and then pour "flowing grout" into the gap and allow it to harden. Then remove wedges.

R

[John Rumm]

Are your new paving slabs thin enough to go on top of the current one?

[newshound]

But the underside will be *very* uneven, I can't see waste pipe surviving, even the thicker solvent weld. It would be scaffold poles for me.

[Robin]

but that looks to me like a 600m flag - perhaps 75 kg. If I'm right the OP's slab is c. 360kg then it's going to need a lot more than 1 of those lifters and 2 blokes.

[John Rumm]

I was suggesting that rather than try and lift the existing one by 50mm, use it as a base and slab right over it. So once the new slabs are down, the original is covered by them.

[John Rumm]

Indeed - at that weight its more like shifting heavy machine tools in a workshop. Lots of small movements with lots of leverage, and propping / supporting at every stage.

[Chris J Dixon]

An issue which hasn't been mentioned yet is the strength of the slab. Is there is any danger of it fracturing under its own weight if only supported at the edges whilst being moved?

Chris

[BillD]

Unlikely given it?s so thick. And easy to be safe by using a vacuum lifter.

[The Natural Philosopher]

Its thicker than many similar cap stones in e.g. passage graves.

[Jim K..]

I need to lift a huge yorkstone flag, approx 4ft by 4 ft by 4 inch thick, by about 2 inches, & rebed on mortar etc as necessary.

I can dig under the front edge if necessary, the sides are flower beds so digging is limited & the rear edge is tight against the house.

Any suggestions on how to approach?

TIA

[Jim K..]

Ha! Though, in essence, is what he was putting under those slabs any different from the canned variety often mentioned on here?

[Jim K..]

Not rocking, it "just" needs raising 50mm to accommodate a new paving scheme.

[Jim K..]

Yeah ta, though what do you lift it with once you've grabbed it with one of those? Access (& cash ;-)) is very tight...

[Jim K..]

Upto 150kg What's it attached to?

Thats 50 quid!!

[Jim K..]

The new are going adjacent to it.

[Jim K..]

"Flowing grout" ? Wossat then?