Originally Posted by
Markus Keller
The problems we have here is that a mortar joint between the brick and lintel never stays tight for long. Essentially, one is attempting to bond (seal) two dissimilar materials,
Actually, the mortar there is not "to bond (seal)" the two dissimilar materials together (mortar does not 'bond' to metal), but for the mortar to serve as a plastic (while not set) material which 'forms to' the brick irregularities and 'forms to' the shape of the support, eliminating 'point contact pressures' which could cause the brick to fail/crack.
Neither is the mortar there to 'seal' that joint, there should be weep holes there, so there is no need nor reason to "seal" it.
Caulk on the other hand will bond to both materials. The caulk will also flex and move as the steel/brick moves with weather changes, thereby staying sealed and prolonging lintel life.
If there were adequate provisions for drainage, i.e., the *required* through the wall flashing which *extends out to the front edge of the steel lintel*, you would not have that problem.
The 'problem' is not the mortar on the steel, the problem is the mortar on the steel.
I.e., "the mortar" *should NOT BE ON the steel*, "the mortar" should be on the through the wall flashing, which *should be* on the steel.