Page 207 - Estimators Piping Man Hour Manual

Section Five

UNDERGROUND

PIPING

In this section we have tried to cover all labor items related to a complete
Installation of underground piping.

First of all, the area in which the pipe is to be installed must be excavated.
Before an estimate is made on this item it is well to know the kind of soil
that may be encountered. For this reason, we have divided soil into five
groups according to the difficulty experienced in excavating it. Soils vary
greatly in character and no two are exactly alike.

Group 1; LIGHT SOIL •— Earth which can be shoveled easily and requires
no loosening! such as sand.
Group 2: MEDIUM OR ORDINARY SOILS — Type of earth easily loosened
by pick. Preliminary loosening is not required when power excavating
equipment such as shovels, dragline scrapers and backhoes are used.
This earth is usually classified as ordinary soil and loam.
Group 3: HEAVY OR HARD SOIL — This type of soil can be loosened by
pick but this loosening is sometimes very hard to do. It may be ex-
cavated by sturdy power shovels without preliminary loosening. Hard
and compacted loam containing gravel, small stones and boulders,
stiff clay or compacted gravel are good examples of this type.
Group 4; HARD PAN OR SHALE — A soil that has hardened and is very
difficult to loosen with picks. Light blasting is often required when
excavating with power equipment.
Group 5: ROCK — Requires blasting before removal and transporting.
(May be divided into different grades such as hard, soft, or medium.)

For pipe installation we have included man hour tables covering cast iron, con-
crete and vitrified clay under this section. For carbon steel pipe installation man
hours refer to section two of this manual.
In many instances specifications may call for the coating and wrapping of under-
ground pipe. This too, has been covered with a table listing the direct man hours
that are required for coating and wrapping various sizes of pipe.

190