[Cob] Drainage question

[Georgie Donais]

All,

I am leading a cob courtyard wall project in my city. We dug a trench, 
lined it with landsape fabric, and we just finished adding the drainage 
system and gravel to the rubble trench foundation. For various reasons, I 
added the gravel until it was six inches below the surface of the ground, 
the minimum depth recommended, planning to start the urbanite stemwall 
there. My problem is that I forgot to fold over/add the landscape fabric 
until we were all done with the gravel. (I intended to do that at least two 
inches below the final gravel, so that the urbanite would sit on top of 
more gravel, not landscape fabric.)

My question is this: should I add more gravel over the fabric, bringing the 
gravel up to four inches below the surface; scrape off some gravel, add the 
fabric, and put the gravel back, or just put the concrete right on the 
fabric? My next work party is tomorrow, so your timely expertise would be 
appreciated!

Georgie
www.cobinthepark.ca