Where a curve changes plane, a vertical slip joint must be inserted.

The mortar joint is replaced by the same bitumen expansion foam that is used at the cill of a panel. The reinforcement rods can be carried through the expansion foam by piercing a hole in the foam and the joint should be caulked with a white silicone, this will visually look similar a standard mortar joint.

Note : Ensure the slip joint is not grouted over in glass block mortar, as by bridging the expansion joint will not allow the panel to expand or contract effectively and may cause blocks to crack.