At the time, even though I was old enough to know better, I thought for
sure what I saw meant that the whole wall was about to fall down,
leaving nothing or maybe just studs and plaster walls around the people
living behind it,
But now I know that bricks are often just facing, and don't do anything
aiui for the strength or structure of some places (especially one and
two story houses, maybe not 4 story buidings built in 1900. )
In true "brick veneer" walls, the bricks aren't structural, which means
that they don't support any weight except for the bricks above them.
However, in a brick veneer wall, there has to be something that supports
the massive weight of that brick veneer.
Typically in steel beam construction, there will be steel I beams that
support the weight of the brick veneer on the exterior of the building,
and in that case you can remove the bricks without the building falling
In masonary work, each layer of bricks or blocks in a wall is called a
In smaller buildings, they bond a wythe of bricks to a wythe of concrete
blocks in something called an "American bond" or a "common bond". In
that case, every 2nd row of concrete blocks is what's called a "3/4
block" where 1/4 of the block is missing. And, each 6th row of bricks
will be laid perpendicular to the wythe and fit into the part of the 3/4
block that is missing. So, the wall will look like normal brickwork
except that every 6th row of bricks on the outside will be laid
perpendicular to the wall, like this:
In this way, the concrete block wythe and the brick wythe are bonded
together for greater strength. But, the bricks can only be replaced
between the layers of perpendicular bonding bricks (the brown bricks in
that image) one section at a time. And then, not the whole section all
the way around the building, but only a few feet of each section at a
If you have no knowledge of concrete blocks in the walls of that
building, it's very possible that the walls are made entirely of brick,
typically three brick wythes thick bonded with perpendicular bricks
every 5th row on both sides of the wall. In that case, it is those
brick walls that support the wooden floor joists inside the building.
Now, it depends on which walls are supporting the floor joists, but if
there's a crack near the corner of the building, then the brick walls on
either side of that crack aren't stable because they're not preventing
each other from moving. Either wall could fall outward at any time,
whereas without that crack, both walls would hold each other in place.
I think you've got a serious structural problem with that building, and
I can see some City building inspector wanting to condemn it before it
falls down and kills a bunch of people.