These are 450 slabs bedded on sand with a 100mm step down towards top of kerb
This is shallow drainage anything 1.2m & above is shallow drainage these are 4 inch pipes also known as 110mm these are the fail drainage that has been placed to concrete bases
This is a drain & kerb line replaced on canvey island this area is prone for flooding as the island is below sea level it also don't help that hardly any drains are connected to the main this is one of 64 we had to replace or repair after repair we also had to re surface round the lid with 6mm Asphelt