CONSTRUCTION NOTES 255 



controlling the method of construction as those outlined under flagstone 

 walks in the previous discussion. 



The first step in the construction of any walk is that of establishing 

 correct lines and grades. These should be permanently established and 

 checked prior to the beginning of any construction work. Stakes (2x4 

 inches or 2 x 2 inches) should be set at least twelve inches outside of the side 

 line of the walk, and usually parallel to the middle line. If the walk is 

 located in a cut or a fill the line stakes should be set outside of the area to 

 be regraded. Grades should be established on these stakes. The following 

 discussion, in order to be as brief and as definite as possible, is subdivided 

 under five headings, which are arranged, as far as possible, without dupli- 

 cation, according as the same method applies to more than one type of 

 walk. 



1. Excavation for foundations of walks. 



2. Subgrading for foundations of walks. 



3. Drainage (surface and subsurface). 



4. Foundation courses and wearing surface. 



5. Curbs for sides of walks. 



I. Excavation for Walks (General Considerations). 



(a) Brick, tile, concrete, macadam, gravel, cobblestone and medina block. 

 Rough excavation may be done with scrapers. All excavation within two 

 and one-half inches of the finished subgrade should be hand work, carefully 

 done with shovels, so as not to cause unnecessary loosening of material 

 below the proposed subgrade. 



If the proposed walk is to be constructed on a fill, such fill below the 

 subgrade should consist of thin layers approximating six inches in depth, 

 and each layer should be thoroughly puddled, tamped or rolled. 



If a heavy fill (exceeding 18 inches in depth) is made, such fill should be 

 allowed to settle for several months (during the winter if possible) before 

 any permanent walk is constructed. In such cases the cinder foundation 

 may be put in place and rolled, and used as a temporary walk until such 

 time as it is advisable to complete the permanent walk. Too much atten- 

 tion cannot be devoted to this question of fill, because any settlement after 

 the permanent walk is constructed would be ruinous to the paved surface 

 and would cause a greater expense to repair than water-bound macadam or 

 gravel walks. The excavation for all walks, the foundation courses and 

 wearing surfaces of which are constructed upon a prepared subgrade and 

 are of other materials than the natural surrounding soil, should be to the 

 required depth as shown in Plate no, figures i, 2, 3, 4, 6; Plate in, figures 

 I, 2, 3, 4; and Plate 112, figures 2, 3. 



