26 



ing, it is possible that the form will have a tendency 

 to "float," due to the lifting action of the wet concrete. 

 We get around that with the shallow footing by doing 

 without a complete form on top. But now such a form 

 is necessary. Probably the best way is as follows : make 

 the footing virtually a step footing by using a series of 

 frames with vertical sides only 5 in. or 6 in. high, 

 made to give approximately the batter required. Put 

 down one frame and fill. While the concrete is still 

 somewhat soft, put down the next smaller frame and 

 fill, and so on till the height is attained. After the 

 frames are removed if the sloping surface is insisted 

 upon fill the steps with mortar and trowel smooth. 



WALLS. 



Forms for retaining walls, curtain walls, etc., will 

 be discussed but briefly. In general it may be said 

 there are two modes of procedure for walls of any 

 magnitude. First, on large buildings, walls may be 

 carried up in comparatively shallow horizontal layers 

 uniformly around the work. Second, complete forms 

 the full height of the wall may be built in limited sec- 

 tions and they are poured full at one time. The first 

 method gives horizontal joints between different sec- 

 tions of concrete, the second gives vertical or irregular 

 joints. The first method means more runways but the 



FIG. 8. SKETCH OF USEFUL BAR FOR SETTING AS WELL 

 AS WRECKING FORMS. 



centering is usually much lighter because the pressure 

 of concrete due to a thin layer is inconsiderable when 

 compared to that due to the head in a deep form. The 

 centering is often built in panels which are raised and 

 used over and over. 



