Flooded area in patio

[rodrialcazar]

Hello,

New slabs and patio was installed last year. It has been OK until this summer where it seems that some slabs have sinked creating a small area of the patio (below the table, in the pics) that now gets flooded when there is medium rain (very often where we are!). Trader is clearly rogue and seems to have gone out of business. Any solutions to this? Is this the trader's fault? Is it feasible to raise the affected slabs, put more concrete below them creating slope, then laying them down again? I have also been told about injecting polyurethane foam, is that a thing?

Many thanks!

 

[foxhole]

Should be laid to encourage run off , if not poor job, you might be able to lift and relay , start with smallest slabs , do you have spares?

 

[Odds]

^what he said^
And i'd prefer to use sharp sand to lift a slab sunk below the patio level which helps rainwater drain away beneath the surface.
I've never heard of using a Poly-whatsit foam for this purpose.

Can you post a pic with a spirit level on the slabs to show how much incline you have?