Relaying old Patio slabs after extension

Mendonky

Hi All,

We have had an Extension to our property; prior to this I pulled up the paving slabs with the intention of relaying them and avoid them getting damaged during the building works and extend the paving into a previously grassy

I have laid small sections of paving for things like a greenhouse but I have two Queries regarding the project-

1) The pictures below hopefully show the edge of the area I'd like to pave- The railing post roughly marks where I'd like to pave to. however, the veggie patch on the other side slopes down and I'm concerned this will cause the sub base to leak out / weather away over time if there is no grass boundary to keep it in after it has been compacted. Will I need some kind of retaining wall below the surface/ slightly above the surface to keep the material in place?

2) The old slabs still have some concrete attached to them which came up with them as they seemed to be laid straight onto soil. do I need to remove the old concrete dabs before they can be used?

Any advice greatly appreciated.

-S

stuart45

I normally build retaining walls to hold the sub base for a patio. Nowadays I run the slabs up to the top course of brickwork, rather than over the top of it.
Clean the old mortar beds off the slabs. When relaying the slabs use a full.bed, not the 5 dab method.

Mendonky

stuart45 said:

I normally build retaining walls to hold the sub base for a patio. 

Thanks for your quick reply- I had a feeling I would need some kind of retaining wall. Any advice on a cheap/ effective way to do this?

My Current plan is to sink some slotted concrete posts and some Concrete gravel boards which I thought would be cheap but seems to be adding up in terms of materials.

Edit: After reading your post again you mention brickwork, I'm assuming you build a Brick/block wall?

stuart45

I normally use bricks rather than blocks. Looks better, easier to get the levels right and stronger. Remove all the topsoil from the area, and work out the height of each corner allowing for a fall in the slabs. Once the brickwork is built fill in with the sub base, compact it and then lay the slabs on a sand/cement bed.