inner leaf

I have a full room height vertical crack in a conc. block inner leaf that I may stitch with helical rods, it has a sand/cement render & skim. What width mesh (expamet) would I put over the crack before new render (and skim)? Presumably this wouldn't need to be stainless mesh as it's not...

re the right hand black line on the wall drawn over the crack with a thick permanent marker; the lintel below that cracked wall is redundant, the opening that required the lintel is now blocked up but still not rendered (image), there doesn't appear to be a corresponding vertical crack in the...