i6 



two half panels, the pieces of sheeting being fastened 

 together by cleats nailed underneath or by nailing the 

 joists direct. The beam and girder sides are not a 

 part of the unit as in the Core-Box type, but are sep- 

 arate units. In the third type no nailing or fastening 

 of floor sheeting is done, except possibly to "tack" 

 down a loose corner or a patching piece. 



The loose pieces of sheeting and the loose joists are 

 easy to wreck and hoist, but will present no saying in 

 labor over the panel type when the latter is intelligently 

 done and will not give as good a class of work. The 

 floor strips are never fitted together twice alike and 

 they warp and split to an unjustifiable extent, at least 

 with any but the best grades of lumber, or with thin 

 unmatched stuff. By using good lumber and having 

 it either matched, or better yet, ship-lapped, the quality 

 of the work is much improved. 



Now as to the actual building of forms for a floor. 

 The beams and girders of a reinforced concrete floor 

 are really great ribs projectig below the slab forming 

 the floor (or roof). A beam or girder, then, has to 

 have a form made, a box or center (the words are 

 synonymous), built of separate parts to be 'erected in 

 place to receive the concrete and retain it till thorough- 

 ly set. These parts must be light enough to be 

 handled easily and rapidly, rigid enough to withstand 

 the great strains due to the dead load of wet concrete 

 and also preserve perfectly to line the surfaces of the 

 concrete, and at the same time must come down easily, 

 with the least possible damage and delay. 



First of all, if there arc girders in the floor, which 

 carry beams, the girder bottoms are made of 2-in. 

 lumber with at least one surfaced side which is next to 

 the concrete. It is cut so as to extend not merely to 

 the outside of the column box, but actually to the face 

 of the column. Then the column side, which is to be 

 wrecked first, will not bind. Perhaps the bottom is 

 so long that it must be made of two pieces. Then 



