(2) Since item 3 has no identical part, one 2 x 6, 10' - 0" long = 10 BF x 3 standard lengths (column 8)
or 30 BF
(3) Therefore, each scrub table contains a total of 63 BF (33 + 30).
Figure 4-3. Consolidated list for scrub table.
4-8.
WASTE ALLOWANCE
TABLE 4-1. Allowances for Waste
Waste allowance, the third essential element
(par. 4-4a(3)) of a bill of materials, is important
because during construction a certain amount of
material is wasted due to cutting, fitting, and
handling. For example, lumber comes in standard
lengths which seldom can be used without cutting
and fitting. Sometimes the piece of lumber cut off is
used, but more often it goes into the scrap heap.
Another example is mortar sand which is normally
stored at the job site. The sand on the bottom of the
pile cannot be picked up without some earth getting
in it. This generally makes the sand unusable and
therefore wasted. Likewise, some electrical items,
(standard lengths, units, rolls, concrete mixtures, and
wire outlets, toggle switches, insulators, and so forth,
so forth) by the applicable waste allowance (table 4-
are wasted due to malfunctioning, wrong size,
1). Then include the result on the final bill of
damage, and so on. Thus, waste allowance must be
materials. (In computing waste, count any fraction
included in a bill of materials to cover unavoidable
from .5 up as a whole number; drop anything less.)
losses. Table 4-1 lists the different allowances for
Ordinarily no waste allowance would be taken on
waste. Note that the allowance percentages are based
items such as scrub table parts. However, if 100 such
on the function of the item. When developing waste
tables were to be built, 500 pieces of 2 x 4's, 10' - 0"
allowances, multiply the total quantity of any one
long and 300 pieces of 2 x 6's, 10' - 0" long would be
particular part
required (results of items 1 and 2 combined and item
3 (fig. 4-3) multiplied by 100). An allowance of 10
4-9
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