The wall was first tested with a bubble level to
see that it was as plumb as possible and to make sure that it was not made to
slope inward to cheat on the dust test. The dust test was to see if
there were any bumps and surface irregularities in the plaster work. The
dust would stick to any area projecting out a little, and would not stick to a
perfectly vertical wall surface.
, the building inspector would come and shake a bag of chalk
dust in the air and then seal the room. 24 hours later the room
was opened and if there was any dust anywhere on the walls, it proved that
the wall was not perfect
Please explain the above. I don't get the connection
between chalk dust in the air and on the walls.
Ralph