The contractor on a current project has been placing the joint reinforcement dry on the bricks before placing the mortar. He says this is how he has always done it, but I'm afraid there won't be enough mortar beneath the reinforcement to achieve proper bond. Should a thin layer of mortar be applied to the wall before putting in the bed joint reinforcement?
No. The contractor is installing the joint reinforcement properly. Placing mortar before the reinforcement is installed creates too much of a delay before the units are laid. The mortar will dry out and develop poor bond. Joint reinforcement should be placed dry on the units, then mortar applied over it. The mason should decide how far to spread the bedding mortar, depending on the weather conditions. In hot weather, this may be limited to only a few feet. As units are placed in the mortar bed, the compression will cause mortar to flow around the reinforcement and develop good bond. Masonry wall ties and anchors, on the other hand, can either be laid dry or placed into fresh mortar. Ties occupy little space, so they don't cause a significant delay between applying the mortar, pushing the tie in the mortar, and placing the unit.