It has creeping rhizomes that in mine, go about 1ft deep at maximum. The true fibrous roots come of these rhizomes but don't extend very far from them.

I can't imagine that this will cause any problems to you whatsoever. It's slow to get going though and prefers a degree of shade.

A faster ground cover would be the dwarf bamboo Sasaella ramosa which is excellent and will grow in sun or shade.

I have pachysandra in my garden too, it's a very useful ground cover.

Thanks for your answer to my query about Pachysandra root depth.
I did imagine it would be best answered by someone who has had experience of the plant.
With the alternative suggestion about dwarf baboo, it will help in my decision making about the best way to progress.

Thanks again.

I have explained that i 'do' have it here, in two areas.
It would be quite suitable for the area you've mentioned.

That bamboo (Sasaella ramosa) also confusingly and annoyingly comes under several names but perhaps the current usage is Arundinaria vagans.