Repointing historic brick (roof, tank, building, electric)

[PreservationPioneer]

I'm considering buying a brick house built in the 1880s. The entire brick exterior was repointed probably 10 or 20 years ago. The brick is in excellent condition, and I noticed no spawling or cracking. The problem is that I believe hard cement / concrete mortar was used. How big of a problem is this? Will it really cause the wall to crumble over time?

[chet everett]

There are a lot misinformed / cockamamie theories that get kicked around the barber shop by oldtimers -- there is some truth moisture getting trapped behind / inside a wall causing problems. Especially when a commercial building with a flat roof has the coping is improperly replaced during a repoint project or the tuck pointing crew leaves no weep holes there can be issues with spalling. A bad crew that left the project open to weather for weeks while they were in the drunk tank is the blame for some failed bricks after a repoint gone wrong, not the kind of mortar used. If the crew knew what they were doing the fact is modern materials can last even longer than the 19th century stuff -- think about back then the lime was probably roasted in a wood or coal fire and had much less consistency. Modern quality quality control uses computerized electric ovens and continous monitoring to produce raw material that are superior. Combined with good techniques and modern water resistant penetrating sealants you should have no worries.

Mortar "hardness" is not a problem if the brick was properly fired in the first place. Is suspect that any problems with brick porosity would have shown up a looooong time ago. Mortar is like any other cementatious product -- more lime will result in stronger product but an improper mix of sand / substrate in the cement can be too brittle. Hard mortar is superior to the crumbling mess that probably was replaced.