Engineering and Construction

Building codes require that Type IV Heavy Timber buildings have floors and roofs of solid wood construction without concealed cavities. Figure 4.18 shows different types of decking used for these purposes. Minimum permissible thicknesses of decking are given in Figure 4.7. To meet code requirements, floor decking must also be covered with a finish  floor consisting of nominal 1-inch (19-mm)  tongue-and-groove boards laid at right angles or diagonally to the struc- tural decking. In some circumstances,  ½-inch (13-mm) plywood or other composite wood panels are also per- mitted as the finish layer.

Figure 4.18