On 19/02/2019 18:36, John Rumm wrote:
On 19/02/2019 16:55, Robin wrote:
On 19/02/2019 16:39, John Rumm wrote:
On 19/02/2019 16:10, Jim K.. wrote:
I need to lift a huge yorkstone flag, approx 4ft by 4 ft by 4 inch
Â* thick, by about 2 inches, & rebed on mortar etc as
Â* necessary.

That's going to be something like 350kg if its a uniform 4" thick!

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

Any suggestions on how to approach?

Sounds like you will need to lever it up from the front edge
(propping as you go) until you can get it on end, so you can relay
the supporting screed.

To relay it, treat it like you would a large shower tray. Slap a
couple of runners into the screed so the tops stand proud of the wet
mortar. Say a couple of lengths of 40mm waste pipe running front to
back. Get and end of the slab on the runners, and then slide it into
position. Then pull the runners out to drop it onto the mortar bed.
You may need someone on a long level to take the weight off the edge
to get the runner out.



If I've found the right density and done the sums right[1] it's around
360kg. I can see 40mm uPVC taking that when spread evenly over the 2
lengths but wondered about when the slab is only partly on. Fill the
pipes first?

Slap some wooden battens down them if unsure. Having said that, I can
easily stand on a solvent weld pipe without crushing it or making much
impression at all - and that is 100 kg as a point load. You could just
use timber, but the pipe would probably be more slippery.

[1] 0.15 cu m at 2400 kg/cu m



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.