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.

The pointing and render look very bad. How old is the house, and can you see the DPC?

The gaps where the mortar has been washed away are typical of lime mortar close to a long-term water leak.

@PigletJohn it's 1930s so I presume this is lime mortar.

Long term water leak sounds v worrying. It's a fairly new kitchen so is it more likely to be cracked old pipes in the ground?

The local water company replaced the water being brought in as they were lead pipes about a month ago. Is it likely that this would have solved the problem or do I need a drain survey?

Not sure how to see the DPC?

It is probably either just above or just below the air brick. It is probably a black horizontal line in a mortar bed two or three bricks up from where ground level used to be when the house was built. You might see it under or beside a doorstep. Once you have found it, it will be at the same level all round the house. Look at other houses untol you recognise one and know where to look.