Plastering Walls and Ceilings.
The occupation of the plasterer is generally united with that of the bricklayer. The business of the plasterer, as such, is to cover over the rough walls and ceilings of a building with plaster, which is the name given to a better kind of mortar, made of lime only. When this plaster is of the coarser kind for the under or first coating, cow-hair is mixed with it to make it bind better. When a plain brick wall is to be plastered, the surface is at once covered with the plaster, this adhering readily to the rough brick-work: but for ceilings or partitions, a groundwork of laths is required to receive the first coating.
Laths are of different sizes and qualities, according to the various work for which they are intended. Those used by the plasterer are termed single, and are about from two to three feet long, an inch broad, and a quarter of an inch thick. They are split out of a coarse kind of deal. Double laths are considerably longer and thicker, and are sawn out: they are therefore regular in their size. They are used for better work in plastering, but chiefly by tilers or slaters.
The single laths are nailed up to the joists of the ceiling, or to the quartering of partitions, with but a small interval between each, so as entirely to cover the surface. The workmen then proceed to cover the lathing with coarse plaster, a labourer supplying them with a small quantity at a time on a square board, held in the plasterer’s left hand by means of a short thick handle stuck upright into the back of the board. The man uses a rectangular flat wooden trowel, with a bridge-shaped handle, to transfer the stuff from the board to the wall, and to spread it evenly over the surface. When the room of which the walls are being plastered is of a better description, the work is floated, that is, a regular surface is obtained by drawing a long straight-edge over the wet plaster, so as to scrape off the inequalities and reduce the whole to a plane surface.
A thinner coating of finer plaster is spread over the first to finish the plastering, and this is again floated in drawing-rooms, and so on.