This term is commonly used to designate plastering that is applied between the studding or rafters to make the building warmer and to keep out the wind. Before the introduction of the present high grades of sheathing papers, back plastering was quite common in the better class of dwellings in the Northern States, but it is now used to a much less extent, as the same object can be more cheaply, and the author believes more efficiently, attained by means of high-grade sheathing papers or Cabot's Quilt.

On the sloping roofs of attic rooms, however, it may be used with much advantage in conjunction with the sheathing paper, and even on the walls it will add much to the comfort of a frame dwelling if properly applied.

Where ordinary sheathing is used to cover the frame and rafters, back plastering should be applied by nailing two vertical rows of laths in each space between the studding or rafters, to the inside of the sheathing, and then lathing horizontally on these strips and plastering one heavy coat of haired mortar in the usual manner. In lathing between rafters 20 inches on centres, three rows of vertical laths should be used. The plastering should be applied so as to come well on to the rafters or studding, leaving no spaces that are not protected.