Floor boards should be laid in courses, beginning at one side of the room and each course, if matched, extending the full length of the room. The heading joints should always be cut so as to come over a beam, and in matched flooring they should break joint in every course.

In laying matched flooring the boards are generally blind nailed by driving the nails diagonally into the upper angle formed by the tongue and the outer edge of the board, as shown in Fig. 326, the inner edge of the board being held by the tongue of the board against which it is driven. In laying the flooring in this way it is obvious that each board or course must be driven up and nailed before the next course can be nailed. The boards should be matched so that they will all be of exactly the same width and fit tightly together, and should be nailed at every bearing, using eight-penny floor nails for 7/8-inch flooring and ten-penny nails for 1 1/8-inch flooring. At the butt joints the nails should be driven through the boards after the floor is laid.

In laying plain jointed flooring it is customary to make straight end joints through three or four courses before the joints are broken, and instead of laying one board at a time several boards are cut and laid in position without nailing and are then strained tightly together by means of flooring clamps or wedges, when the outer board is first nailed, and the other boards afterwards.

With jointed flooring the nails must be driven through the board and sunk with a nail set, if the floor is to be dressed off. A pencil line should be drawn with a straight-edge above the floor joists so that the nails will enter the joists and also be driven in straight lines across the floor; two ten-penny flooring nails should be driven at each bearing. Jointed flooring can be laid with closer joints than common matched flooring.

196 Laying And Nailing 200205

Fig. 326.

Traversing. - Floors that are to be finished in oil, wax or varnish should be traversed by hand, that is, planed crossways of the boards, so as to bring the floor to a perfectly plane surface. Special planes with long handles are made for this purpose. For floors that are to be carpeted it will be sufficient to simply plane off all ridges made by the edges of the boards.

Kiin-Drying. - All hard wood flooring, and all soft wood flooring that is to be finished, should be thoroughly kiln-dried (see Sections 12 and 13) and should be laid as soon as possible after it is delivered, and should not be delivered until the plastering is thoroughly dry.

Flooring that has been well kiln-dried is often put into a damp building and allowed to remain several days before it is laid ; under such conditions the wood rapidly absorbs the moisture in the air and all the beneficial effects of drying are counteracted, so that when the building gets well dried out the floor boards will be found to have shrunk, leaving wide cracks between the boards. This is an important matter in securing good floors and should be carefully guarded against by the superintendent.

Hard Wood Floors in Patterns. - Hard wood floors are sometimes laid with short pieces in ornamental patterns by the carpenter. Fig. 327 shows common patterns that may be laid with ordinary 3 inch matched flooring. The mitre joint shown at A is the cheaper, as it does not require matching the ends of the pieces- The joint shown at B has a more pleasing appearance, but requires that the ends be tongued and grooved. If the pattern is to be more elaborate than the one shown, it will be more satisfactory to use regular parquetry flooring.