10 



beams and girders. Green concrete beams and girders 

 should not be required to bear any loads for a con- 

 siderable period, hence the necessity to leave their 

 supports in place undisturbed. 



All lumber except that for shoring and bracing 

 should be surfaced at least on one side and the edges. 

 It is better to have chamfered corners of girders and 

 columns, although in many cases it is not necessary. 

 This is done by placing triangular pieces in the forms 

 tacked lightly in place. 



Avoid excessive use of nails. Nails must be used 

 to batten together the pieces in a girder side, or in a 

 column side, in forming panels where necessary, and 

 in many other ways. But for braces or cleats or other 

 parts which must be torn apart, especially when lum- 

 ber must be used over and over again, use as few and 

 as small nails as possible to diminish the labor cost 

 and increase the life of the lumber. 



Column forms have to resist very great pressures 

 due to the depth and weight of wet concrete. They 

 should be made of 2-in. stuff and held together by 

 collars made of 2 x 4-in. pieces, four such pieces being 

 necessary for a collar. They are cut considerably 

 longer than the outside dimension of. the column box 

 so that they overlap and are fastened by nailing blocks 

 on the ends and by wedges. These are very easily 

 assembled and knocked down. They should not be 

 more than 24 in. on centers vertically. Long bolts, 

 holding together collar pieces on opposite sides may 

 be used, but will be expensive except on very large 

 jobs. 



Sheet metal column forms are rapidly coming into 

 use for circular columns. They are high in first cost, 

 but are easily handled besides being adapted to use 

 for several sizes of columns if properly designed. They 

 are used in sections so as to be adjusted without diffi- 

 culty to any length of column by overlapping sections. 

 They are restrained against bursting pressures by 



