The Plan Of The Roof. (Fig. 70). In laying out the plan of a roof, it is best to be governed by the greatest rectangle that can be obtained from the plan of the house, angles and projections being framed by means of hip rafters (a) or valley rafters (b). This roof contains all the rafters and cuts necessary for framing any rectangular pitch roof of equal pitches, though the principles involved may be applied to any angles or to any combination of pitches.

Fig. 70. - Roof Plan.

In laying out the rafters and cuts of a roof, a plan or sketch showing the location of every piece entering into its construction should be made, unless the roof is a very simple one. If an architect draws the plans of the house, a roof-framing plan is generally furnished. The safest plan is to estimate the lengths of the principal members of the roof before commencing work, as the men may more easily be kept working to advantage; in fact, this should be done, in order that lumber of the dimensions which will cut most economically may be upon the ground ready for work.