What should I use between patio slabs beside the house wall?

[KiwiKola]

I'm getting all the weeds out between the patio paving stones and was wondering what to do beside the wall of the house?

Would polymeric sand work here too? It used to have a concrete piece along the wall and where that still exists there is not damp/soil/weeds but that has mainly gone.

Should I pull off the render where it is cracked by the damp bricks?

I'm going to remove the bubbling paint as well - a couple of areas the mortar is pushing out from the brick.

It's hard to see exactly what it is like but a client of mine is buying exterior terracotta tiles that look like bricks to cover a similar area. The problem is where to finish the render as you want a straight line ideally.

Perhaps a thick beading of some kind could cover the joint and any irregularity in the render line.