Among the many other bits of info that we received from Mario Machnicki, he advised us to become familiar with Preservation Brief 2, a publication from the National Park Service that is pretty much the bible for masonry repair of older buildings.
The link above is to the web version of the document. You can also can order hard copies of up to 5 briefs for free from the list on this page.
We attended the HCBA masonry seminar on Thursday, held at the Sulzer Library, and taught by the very knowledgeable and entertaining Mario Machnicki from Marion Restoration and the U.S. Heritage Group. The differences between traditional masonry with softer bricks and lime mortar, compared to modern masonry with hard bricks and cement mortar was fascinating and really rather alarming. And like so many things, it all comes down to moisture.