Page:Cassells' Carpentry and Joinery.djvu/107

 Rh A board placed over the loose boards, as seen in Fig. 368, will be found of assistance in getting the floor-boards down to the joists, but there will still be some difficulty unless the four boards are kept loose—that is, none of the intermediate boards between the first and sixth must be nailed until all of them are tight home. Another simple method of cramping is shown in Fig. 369. An iron timber dog (Fig. 47, p. 11) is driven into the top edge of the joist, allowing about 3 in. from the edge of the floor-board. A piece of rough timber 2 in. thick is then laid next the board, and a pair of hardwood folding wedges is driven between the timber and the dog until the joints of the board are close; then the boards are nailed, the dog is removed, and more boards laid in the same manner. Both the methods above mentioned are usually adopted for the commoner kinds of work only.

Fig. 372.—Improved Form of Floor Cramp.

Fig. 374.—Floor brad.

Fig. 373.—Another Improved Floor Cramp.

Fig. 375.—Butt and Splayed Heading Joints.

Laying Floor-Boards with Aid of Cramp.—Floors laid with the heading joints crossed, as in Fig. 370, need a special cramp to bring up the joints; three kinds of cramps are shown by Figs. 371 to 373, but a variety is available. For instance, batten-width tongued and grooved common Baltic flooring would be laid in the following manner. The joists would be tried over and brought to a level. A batten, or line of battens, would be laid down next the wall to line true at the outer edge, and then be nailed to the joists. The remaining rows are laid two or three at the time with the tongues inserted, then cramped into place, nailed, and the next lot of battens applied. If the battens are already tongued, they can be laid either way, as the block, or saving piece, between the cramp and batten can be grooved to clear the tongue. Figs. 371 and 372 show the modes of using floor cramps. When the floor has been finished so far that there is not sufficient room for the cramp, the remaining