Page 162 - Moving the Earth_ The Workbook of Excavation
P. 162
BASEMENTS
4.2 THE WORK
FIGURE 4.1 Protection for tree trunk.
FIGURE 4.2 Topsoil piling.
Artificial Obstacles. Serious digging difficulties may be caused by obstructions placed by
the builder. Batter boards are used for reference in exact placement of foundation walls. They will
increase the excavation cost by restricting the movement of machinery, particularly if the house
is to be irregular in shape. Piles of building material may also be much in the way.
Corner stakes, with back reference points such as are described in Chap. 2, are adequate loca-
tion marks for the excavator, and other preparations for building should be postponed until dig-
ging is complete.
Depth. The depth of the excavation depends on the first-floor height relative to original grade,
and the depth of substructure below it. Substructure might include floor thickness, rafters, sills,
