The Brew Cabin

Hi Tony, I'm a new member and I'd like to start off by saying this is absolutely the most comprehensive and informational site I have found in my weeks of scouring the internet!

Now my question: Are retaining walls (block type) and/or stacked stone walls suitable to use as edging to contain pavers for a 25m2 backyard patio? And if not, how difficult is it to pour the mass concrete bed and haunch? Do you need to build forms to pour the concrete into, or do you just plop the concrete down on the sub-base and roughly shape it in with the trowel?

Any wall that's above 450mm high is usually stable and strong enough to contain an area of residential paving. If it's proper brickwork/masonry (ie mortared joints) then it will be fine.

Stacked stone walls (dry joints) are ok if there is sufficient volume/mass in the structure to restrain the edges, which is why I give the 450mm figure. If in doubt, laying the edge courses on a bed of concrete and then packing the gap between the blocks and the 'wall' with concrete or mortar will be extra insurance.

You don't need to go to any deal of trouble when laying the edge courses on concrete. Use a semi-dry mix, place it with a triwel or shovel and roughly level it out. No need for formwork, and it's better not to use a wet mix.