When the grounds and corner beads are in place the building should be ready for plastering, as no finished work should be put up before plastering if a first-class job is desired.

Before the plasterer commences work the carpenter should close all outside openings by hanging temporary doors at the entrances and covering the window openings with muslin or old sash. If the weather is not too cold muslin is the best material for closing the window openings, as it allows a sufficient circulation of air to carry off the moisture produced by the drying of the plastering without a decided draught. In very cold weather part of the openings should either be tightly boarded up or filled with temporary sash. (Old sash, when available, are often used.) Store fronts should be boarded up on the outside, so that the front may be finished without removing the boards.

The architect should not allow the permanent sash to be put in until the building is plastered and dried out, as the moisture from the plastering is sure to swell them, and, even if tightly fitted, they are sure to shrink after a time so as to be very loose. The sash also get more or less stained with plastering, which is never entirely removed.