A subfloor should be laid first using shiplap or sheathing. Over this a
finished floor of such hardwoods as maple or oak, or the harder softwood
species such as Douglas-fir, western larch, or southern pine, may be
laid. Vertical grain and flat grain may be had in both softwood and
hardwood, but the vertical grain shrinks and swells less than the flat,
is more uniform in texture, wears more evenly, and the joints open much
less. Finished flooring consists or tongue-and-groove material of various
thicknesses and widths.
Despite a slight tendency to splinter and wear irregularly over a period
of years, plain wide planking of random-width boards makes an appropriate
floor for a log building. An attractive effect may be had by using screws
instead of nails, countersunk to a depth of 1/2 inch and concealed by
inserting false wooden dowels glued in place as shown in figure 23, _B_.
Keying the boards together with wood keys, at random along the edges,
adds to the attractiveness of the flooring.