Flag on edge - Weight of flag on wet concrete

[Focused]

The small patio I will be building extends into the current soil/planting area of the garden almost at the same level and I was thinking of building a very small wall, just two courses, to hold in/separate the patio foundation material from the soil. The edge of the patio will sit on top of the wall. I have some concrete edging slabs 3 ft long and 6 inches deep that I could use as an alternative to bricks and I have been looking at the Flag on Edge section of the main site. Might seem a daft question but won't the weight of the edging slab make it sink into the poured concrete, if only a little, making it difficult to retain the desired levels at the top edge? Or would this not happen with a very stiff mix? I'm sure that you guys just love waiting for silly questions to come in!

[msh paving]

Just use a semi-dry mix of concrete to hold them to line and leval, no problems that way MSH

[ken]

Use a semi dry mix. 5-1 grit sand/cement. Bop the edgings down to required level, then back them up with concrete and they will be reet.

[oioisonnyboy]

pardon me if I have misunderstood...but are you intending to use the concrete edging to stop the sub base (as you call it the foundation of the patio) from moving out into the soil of your planted area?

[ken]

That was my understanding of it too Oioisonny boy, if the paving isn’t to be retained by the edging then make sure you set the edging low enough to set the flag/block on a bed of mortar, as just sitting on the edging wont work.

[lutonlagerlout]

we do a lot of these for the council and the rule of thumb is at least 30% in the ground
you can buy 600 by 300 and 600 by 450 council greys for just this instance
very spartan and functional
bricks look better
BTW leanmix concrete for the bedding and wetter gear for the haunching
LLL

[Focused]

Thanks guys' great tips. Yes Ken re your second post, I intend to use mortar for the last row of paving taking it on to the top of the edging.

[Mikey_C]

as a diy'er who was done flag on edge it ani't that difficult but a the dry mix is the key wetting it up for the haunch as LLL says.