Drain for patio slab touching wall - Water logging next to wall near patio

[Orchid]

Hi
We have recently built an end to end patio using natural sandstone where the patio edge touches the house wall.
There is no drain or gravels between the patio slabs and the wall.
The patio is 2 bricks below the DPC level.

The patio is roughly 3 m wide and is followed by a lawn which is 6 m wide.
I have started seeing little water logging in the sand fill between the slab and house wall.

The contractors are still on site and I want to know whether this can be a problem long term.
Should we ask the contractors to make any changes to the edge?

Thanks.

[seanandruby]

Which way is the fall?

[Orchid]

The fall as in the slope is supposedly away from the wall towards the lawn.
But it since the slabs are tumbled natural sandstone , water does not run down quickly and gets collects in the grooves of the slabs.
Also the sand fill in the wall/paving edge is slightly grooved/concave.

[seanandruby]

Is it sand or mortar. Seems like the contractor has done his job and is on compliance with 2 below. If your concerned post a photo or 2 up.