paving brick border - dry mix concrete or hardcore/sand?

[mullerriceman]

Hello All,

I've had a look using the search function for this in the garden section but can't find anything that fits - so i hope someone out there can help

I'm planning to put a paving stone border in to separate the flower beds and grass. Having received some interesting quotes for the job I figured this might be one I might do myself to keep costs down.

I'm planning to use a trencher which digs up to a foot deep and 4 inches wide. The paving brick I'm using has a width of 3 1/2 inches. I plan to use a spade, if needed, to make the trench a little wider.

The ground I'm working with is heavy clay - hence the trencher, otherwise it'd take me a month.

My question is this - can I get away with using 2" compacted hardcore (compacted with a board and hammer) and 2" sand or would using dry mix concrete be the best way?

I'm a bit of a concrete mixing novice so would prefer option number 1, but I'm worried about the hardcore/sand moving in the clay soil after a year or two and then having to redo the thing again.

I'd appreciate any advice at all

 

[wrathkeg]

IMO you are over engineering. No need for hardcore, or even cement really:

http://www.pavingexpert.com/edging4.htm

 

[r896neo]

Lay them on 3 inches of semi dry leanmix concrete as you would a small kerb.

 

[mullerriceman]

thanks for the replies - as regards the drymix, the webiste which was linked to suggests a 6:1 mix.

Is it possible to dig a trench for the mowing strip (4" deep, 4"wide), pour the sand in, then pour the cement in on top, mix it in the trench, then water it down, then put the bricks on top?

I'm not trying to be lazy or avoid using a cement mixer, just thinking about doing it the easiest way of forming up the mix.

**
edit - I've just watched some concrete mixing videos and I think the cement mixer is the way to go

 

[r896neo]

you must mix it. you also add some water. if the mix is too wet it makes it turn to soup when you tap your blocks down into it. if its too dry it won't harden properly.

It should be the consistancy that when you squeeze a ball of it in your hand it doesn't ooze water but when you release it it should stay in a ball and not crumble apart.