The brick wall in question is a free standing garden boundary wall. The top few courses need repairing, as water/frost damages has caused bricks to come loose, and in some cases bricks from the top course are missing completely. Currently the wall consists entirely of what I would call normal brick, but I am considering better options. The wall is around 6' high, and a single brick thick with supporting pillars, if that makes any difference.
It seems clear to me that concrete coping would be the best solution for preventing future water damage, but for various reasons I am considering other options.
Would a top layer of solid engineering brick offer protection against water damage that is better than normal bicks? I understand engineering bricks are less porous, but isn't the damage mainly done by weakening the mortar in the top layers? In which case the type of brick might be of little significance.
A neighbour has suggested a cap of mortar on top on the wall. Would that help at all? I have my doubts!
Are there good alternatives to mortar that will give better water resistance for use in the tops layers.