Hugo Nebula wrote:
On Fri, 11 Sep 2009 02:07:50 -0700 (PDT), a certain chimpanzee, "Man
at B&Q" randomly hit the keyboard and
produced:

A buttress is load bearing.

Isn't it more that common usage has come to interpret "load bearing"
as supporting something above rather than supporting something to the
side?

In the sense that load = a force acting on an object, then yes, a
buttress is load bearing. However, I did want to point out that a
structural member does more than react to gravitational forces.

Ultimately in a building, there are no others.

Except maybe in prestressed concrete, where the stress is in the form of
tensioned steel, or in groundwork where its soil movement due to
humidity changes, and occasionally one takes wind stress into account,
but these are specialise areas. In the end the rest of the forces are
all due to gravity. They may not be straight down, that's all.

Buttresses are directly about the roof weight on arched, ridged or domed
rooves. They are there because masonry does compressiion wonderfully,
but is crap in tension, and hence bending.