"J.A. Drew Diaz" wrote:

> 100 yrs just a WAG.
> Anywhere but Manhattan this building would have been put out of it's
> misery...
>
> "Becker, Dan" wrote:
>
> > Eric's suggestion is a good one; I agree that cavity construction on a
> > 3-wythe 100-year old brick wall would be an unusual situation. But to
> > answer your question, Drew, the purpose of the space in modern cavity
> > wall construction is to provide a path to direct condensation out of the
> > wall. It allows you to control where the dew point occurs in the system
> > and where condensation happens, and through the use of weep holes and
> > proper flashing, direct the water out of the wall to the exterior. When
> > sloppy masons fill the space with mortar, it affects the performance,
> > obviously. The air space is also given consideration in analyzing the
> > energy performance of the wall; it adds an insulation value.
> >
>
> that's basically what I recall from classes in the dawn of time-
> someone recently suggested it was because there were lumpers putting up the
> core
> and finishers putting up the facade..