"J&K" wrote in message
oups.com...
I am thinking of putting a new patio in my back garden, over the
existing slabs. Whilst this is okay from a damp course perspective the
existing drains and grids will obviously be 1 1/2 inches below the
level of the new patio once I've finished.

Is there an easy way to raise the level of them?

No easy method that doesn't involve extra brickwork or a layer of concrete
under the existing surrounds to the manholes.

Why not add a grid to the top so it's removable and fill with pea shingle
for an area to put decorative pots on etc?