Paved patio: Random rocking slabs and loose edge stones...

[Obiwanquinnobi]

Hello there

Hoping that someone can give a bit of advice as to how to tackle the odd loose\rocking paving stone and also how to secure the edge stones on my patio.

I recently removed all the old cracked and loose grout and want to replace it but I know that if I do that it will crack again the areas I have loose stones.



There is the odd stone here and there that rocks and also some of the slabs round the edge move a little.

The patio is paving stones on a sand base and I have tried to re-seat a single slab this evening as in the picture but I can't seem to get it to stop rocking. I tried to get the area flat, level and compacted but there always seems to be some rocking movement. Grrr

Any tips\tricks to re-seat the stone(s) on the sand without it moving around or rocking? Or are there any other ways to do this? Would just totally removing all the sand down to the hardcore, then filling with a mix of wet concrete do the job or is this a bad thing to do?

I also have to find a way to get the edge stones to seat properly without movement as there is no pin kerb. In some areas of the patio, they've been concreted in using flaunching so they are pretty solid. Not sure what the best approach is to get the rest on par.

I really don't want to have to re-lay the whole patio if I can help it as money is tight at the minute.

Any ideas ?

Thanks in advance and sorry for the rambling, lengthy post.

 

[Keithmac]

Have you tried digging 10mm out tamping flat and using a drymix?.

My patio was leveled + tamped 10mm (small) gravel, with drymix on top (4 sharp sand 1 cement) its rock solid.

The edges you could dig down and fit kerb stones or similar, or cement the last 2 inches to stop the sand falling out of the end and destabilising the flags.

 

[Obiwanquinnobi]

Have you tried digging 10mm out tamping flat and using a drymix?.

My patio was leveled + tamped 10mm (small) gravel, with drymix on top (4 sharp sand 1 cement) its rock solid.

The edges you could dig down and fit kerb stones or similar, or cement the last 2 inches to stop the sand falling out of the end and destabilising the flags.

Thanks for the reply Keith,

To answer your questions:

Yes I tried digging out that single stone in the pictures and and replaced the sand \ tried to flatten\tamp down with a block of wood (with the edges cut to overhang the adjacent slabs) I though this appeared level, I still get rocking when I carefully reseated the slab. Maybe a tamping tool like this would be a better solution? https://www.amazon.com/Fibreglass-Earth-Rammer-Tamper-200mm/dp/B003CT4DD6

Putting kerb stones in might be difficult due to the restricted space (Fence in the picture) but I might look at concreting the edges in.


What kind of mix ratio would be best for a dry mix or wet concrete for this job? 1:4 be suitable ?

Thanks again

John

 

[lonner]

You need to fluff the bed up a little.
This will allow you to compress the slab to a desired level.
A rocking slab is simply due to the bed in one area being high.

Edge slabs are best set in wet mortar.