Fig. 123. Pitch Board.
Fig. 124. Economical Center Stringer
(5) Joint one edge of each stringer straight and square and place the framing square as in [Fig. 122] and scribe along both blade and tongue. (6) Scribe the line A parallel to the 9" run, at a distance from it equal to the rise diminished by the thickness of the proposed tread. (7) Continue to lay the square as in (5) until the required number of steps have been laid out. A pitch board might have been constructed and made use of instead of the framing square in laying out the stringers. This is nothing more than a piece of stock which serves as a template by which to lay out the rise and run of each step, [Fig. 123.] A cleat or fence nailed to one edge after the three edges have been planed to dimensions permits easy and accurate placing of the same.
(8) There remains the sawing out. On open stringers this is done by sawing square across the board or plank. Where the exposed ends of risers would make a bad appearance, the cuts in the stringers for risers are made mitering and the ends of the risers are mitered correspondingly. In either case the end of the riser will be flush with the exposed side of the stringer or string.
[Fig. 124] illustrates an economical way of constructing a center stringer, a 2" × 4" having nailed to its top edge the waste cut from the side or wall stringers.
Fig. 125. Stringer for Attic Stair
61. Risers and Treads.—Upon the common stair, such as attic and porch, etc., treads and risers are placed as in [Fig. 120], being nailed to place, risers first and then treads.