Laths.

Laths. Laths are small strips of wood of various lengths, rarely more than 4 feet; they are made either by splitting lathwood, which is the Norway spruce fir (Pinus abies), or else they are sawn from Canada deal. The sawn laths are a modern introduction, due to the development of steam sawmills in Canada, which thus use up the small portions of the lumber. Laths are used for nailing to the uprights of partition-walls and to the rafters of ceilings; they are placed slightly apart to receive the plaster, which, by being pressed into the intervals, is retained, and when dry is held securely on the wall. Slaters' laths are longer strips of wood, nailed on to the framework of the roof, for the purpose of sustaining the slates, which are fastened to the laths by nails.