Have I dug this ditch deep enough?

[DaveG]

So we’ve finally got the weather for me to start tackling the high outdoor ground levels. This area had thick concrete slabs so my plan originally had been to shift them across away from the house but on lifting them I found a concrete slab underneath. I’ve pulled up the slab and removed maybe an inch of topsoil which doesn’t seem a lot but the 3 layers removed combined have brought the ground level down quite a bit. I’ve laid weed membrane down now and was thinking about laying stone back up by around an inch and a half or so. Does this look enough in relation to the subfloor vent?

 

[Kearn]

6 inches is the rule of thumb… however, the ground level needs to run anyway from the buildings that level, just cutting a small channel isn’t really going to cut it.

You need to be careful not to dig yourself a moat, the outer wall needs to remain dry not just lower than inside.

 

[DaveG]

Thanks Kearn. Is that a reduction of 6 inches in ground level or ground level should be 6 inches lower than the bottom of the subfloor vent?
The rest of the slab will be coming up eventually, this is just a short term move to continue drying the house out where possible. That’s 2.5 courses of stone there that can now breathe to atmosphere that were previously locked in by cement