Rhizome/stolon depths for creeping perennials

This is my first post here; forgive me if the information is already
available (and point me at it).

I'm planning to install some perennial ground cover plants in some
new landscaping, and am looking at some fairly 'aggressive'
creepers which I wish to keep out of adjacent lawns (mine and
various neighbors').  I have been so far unable to determine
just how deep I'm going to need to put my barrier because I can't
find listings of rhizome depths for much of anything except turf
grasses (a couple of inches) and canes (30-40 inches).

Can anyone point me to (hopefully) a single source for rhizome
depths for the common perennial ground-cover plants (e.g.: vincas,
pachysandras, verbenas, delospermas, worts)?

Oh, and another question -- what materials can I use for a long-
lived deeply-buried barrier?  Aluminum tends to dissolve underground
in my yard; how about PVC (siding or heavy sheeting), polyethylene
sheeting, asphalt roll roofing material, or what?

Thanks in advance

Mark Shumaker 

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