I'm going to replace these cracked bricks on the front of my home(see pic). What type of mortar should I use? Type S, N, or M? Is there a way to determine the type of mortar that was used when the home was built?
The mortar should be matched to the brick hardness (or stone hardness).
A soft, reclaimd brick might be matched to a Type N (750 PSI)
The type S, at 1800PSI would be my guess for these bricks.
The M, at 2500 PSI would probably be too hard.
A great tutorial from the Nation Park service: