I need recommendation for type of mortar offering good grip to repair old deteriorated mortar between masonry squares with a hole in the middle used for the balcony wall. This is a 20th story balcony in a Houston high rise building built in the 70s. The gaps are about 3/4 inch. Owner is responsible to fix the inside of balcony. The outside seems OK.
In addition to the mortar, I was thinking to use a stainless wire to wrap around the masonry square to add additional strength wherever mortar is replaced. Thank you.
Best Answer
Sounds like a pretty standard repointing job, other than the location - rake, chisel (or "grout-saw") out all the loose/deteriorated mortar to some convenient depth, wet the joints, pack in new mortar (keep it damp so that it cures, rather than drying out) and tool the surface. You'll find more information in general on "repointing brick" but it's essentially the same other than your joints may be a bit wider than a typical brick joint mortar-line.
1970's era construction is probably normal modern Portland cement based mortar. i.e. what your masonry supplier will have as mortar mix, not some weird old lime-putty stuff you might need for historical preservation, where using the modern stuff will cause problems since the wall was built with the old-style stuff.