Page:Cassells' Carpentry and Joinery.djvu/90

72 would be used to connect the staircase trimmer and joists shown in well. Fig. 317 (p. 70) gives a view of the herringbone strutting (2 in. by 1½ in.), four rows of which are indicated on the plan. The joists going from back to front are required to be



34 ft. 9 in. long; therefore all, or the greater part, would have to be formed of two lengths and halved on the middle bearing; alternative methods of doing this are shown by Figs. 318 and 319.



In projections where fireplaces and flues (usually known as chimney breasts) occur in walls it is necessary to trim round them, so that the nearest timber in front shall be at least 18 in. distant, whilst that at the sides may be only an inch or so. In the plan (Fig. 315) the trimming joist runs parallel with the chimney-breast, and the trimmers which carry the joists are against the sides of the breasts. Fig. 320 is a reverse case, there being only one trimmer, which is parallel to the breast, but two trimming joists, these being at right angles to



it. Fig. 321 is a section through the trimmer, hearth, coach head brick arch, etc., shown in plan at Fig. 320. (Fig. 321) is a feathered-edge piece of board (a springing piece) nailed to the trimmer for the arch to butt against; is a fillet nailed to the trimming joists so as to support the piece of scantling to which the laths are nailed. This construction is clearly shown at (Fig. 322). When a trimmer has to support an arch, to prevent any likelihood of the arch forcing it back, one or two iron bolts are inserted, one end being bedded and