Helifix DryFix wall ties are power driven directly into both leaves, via a small pilot hole of around 6mm diameter.
Or Helifix RetroTies are driven into a 4.5mm pilot hole in the far leaf, via a clearance hole in the near leaf into which they are bonded with Helifix PolyPlus resin.
Or Helifix ResiTies are resin bonded into a 10mm hole in both leaves.
