means of 9 X 5%-in stud-bolts cast in the concrete and projecting about 4 in. The top of the form is braced by stays running to adjacent columns, and by inclined supports nailed to a floor-block which is held in place by means of another 95%-in bolt cast in the concrete floor. Fig. 11 shows the erection of this type of column-form on typical building work, and Fig. 12 a similar construction applied to a large grand-stand.

There are at present a number of different types of STEEL-COLUMN FORMS ON

the market which are very satisfactory for casting round columns, particularly those with flared capitals, such as are a customary feature on girderless-floor construction; Fig. 13 illustrates typical work. In all column-forms provision is left just above the floor-level to permit cleaning the interior immediately before pouring the concrete.

(c) Slabs, Beams, and Girders. Girder-forms are ordinarily made continuous from column to column, and the beam-forms, resting upon cleats nailed to the sides of the girder-troughs, carry ledgers which in turn support the JOISTS OR

SPREADERS of the floor-construction. Fig. 14 illustrates a typical arrangement. In cases where it is possible to re-use the floor-forms without material alteration, as is usually the case, they should be made up into panels of convenient size. The vertical SHORES, OR POSTS, supporting the floor-system, are usually of rough stock 4 X 4-in section. 2 X 4-in material may be used to advantage for light work, but requires more bracing and is generally less satisfactory.

6 X 6-in posts are occasionally used for very heavy loads, or high stories, but are not often required. The beam and girder bottoms should always be of 2-in stock. The sides of beams and girders may be of -in boards, but are preferably constructed of 12-in material or even 2-in material, as the latter requires less bracing and is less subject to warping or bulging.

The lumber used in constructing both the bottoms and sides of the BEAM AND GIRDER-TROUGHS should be planed on all four sides except that, where moldings are used along the lower edges of the beams, or girders, the bottom

board may be unplaned upon the edges, thereby obtaining the full nominal width. The CLEATS upon the sides of beams and girders, see Fig. 14, can be of 1 X 4-in or 1 X 6-in material, spaced about 2 ft 6 in on centers; the LEDGERS are 1 X 4 in, 14 in or 2 X 4 in; rough stock is used for both cleats and ledgers. It should be particularly noted, however, that the FINISHED THICKNESS of the

Courtesy Atlas Portland Cement Company

Fig. 14. Typical Wooden Forms for Beam-and-Slab Construction

boards forming the beam and girder sides must be UNIFORM, and the ends of the spreaders supporting the floor-panels should be sized to a uniform thickness in order to insure a level floor. This latter operation is usually accomplished upon the job. The floor panels or decking, as sometimes called, are built up of 3 X 6-in tongue-and-groove roofers nailed upon spreaders which have a maximum spacing of about 2 ft 6 in, governed by the ALLOWABLE SPAN of the