Winter Jasmine roots - East facing wall saga!!

Hi all

Some of you may have seen my post about getting rid of the Winter Jasmine on my East facing wall and replacing it with probably Daphne and Dublin Bay roses. This pic is the Winter Jasmine before I tackled this job.



I cut it down and poured some Brushwood into the stem, but decided to investigate the root before planting anything new. The depth of the bed (out from the wall) is 20cms. Here's whats emerged.



I've dug down almost 20cms, but still nowhere near the bottom.



The main stem is growing through this this hole into the house

So my question is:

Will the Brushwood manage to kill this size root and if so, how long before I can plant new shrubs/climbers? Would appreciate any (and all!) advice