Phlox Subulata - how far will it creep (over rock/concrete)

Hi all,
I have searched this question, haven't found an answer, though a couple of images found by 'net search suggest creeping Phlox will grow over and cascade down a stone wall.

What I wanted to know is how far will Phlox Subulata (creeping Phlox) cover over say brick work or concrete.  We've a brick wall, one brick deep (longways) so 8" or 20 cm plus some other concrete work for a few more inches.  Clearly nothing is going to actually grow on that, except for maybe moss and lichen.  Would Phlox actually cover that and even cascade down over it?
I suppose, given enough time, it might cover some of that.  I suppose I really should cut some of the bricks back, and maybe the concrete foundation under it, to have some bare soil for the Phlox to grow into.

Would be interesting to read or even see of any examples where this plant grows over solid objects.

Thanks