television receptacles, fixtures, and any other items, such as
snow-melting mats.
It is the estimator’s job to determine exactly where
the responsibility begins for the wiring. Does it begin at
the property line, at the structure, or 10 feet from the
structure? If a transformer is required, who pays for it,
who installs it, and who provides the base on which it will
be set?
Different types of construction affect the installation
of rough and finish work. When using steel joists, there is
usually ample space through which to run conduits easily.
Cast-in-place concrete requires that there be closer coop-
eration between the general contractor and the electrical
contractor, because the conduit (as well as sleeves) and
fixture hangers often must be cast in the concrete. The use
of hollow-core, prestressed, precast concrete causes other
problems, such as where to run the conduit and how to
hang fixtures properly. The conduit can be run in the
holes (or joints) that are in the direction of the span, but
care must be taken to run them in other directions unless
the conduit can be exposed in the room. These problems
greatly increase the amount of conduit required as well as
the cost of the installation. If installation is difficult, it
also becomes more expensive. Similar problems occur
when using precast double tees, except in that case no
holes are available in the spanning direction. The problem
can be alleviated to some extent by pouring a 2^1 ⁄ 2 to
3-inch concrete floor over the slabs in which to run the
conduit.
One last point: Estimators must not guess the price of
fixtures. Prices vary considerably. What seems to be an inex-
pensive fixture may be very expensive. They should never
trust guesswork, but rather check prices.
Light fixture manufacturers often prefer not to give
anyone but the actual electrical subcontractor a firm
price; however, if estimators are insistent, the manufac-
turer will cooperate. This is one reason why it is impor-
tant to be on friendly terms with as many people as
possible. Others often provide the key to success in what-
ever job is being bid.
The selection of an electrical subcontractor should not
be based on price alone, although price is an important con-
sideration. Other factors, such as the speed with which the
subcontractors complete their work and the cooperation
they show in dealing with the prime contractor and other
subcontractors, are also important. Nothing causes hard
feelings faster than subcontractors who are uncooperative.
Because prime contractors are responsible to the owners for
all work, it is in their own best interest to consider all factors
while selecting an electrical subcontractor.
The major areas of coordination required between the
electrical contractor and the general contractor are outlined
in Section 17–4, while Figure 17.1 shows typical electrical
symbols and abbreviations.
When electrical subcontractors bid a project, they are
often asked to include required temporary wiring and
lighting. By having the electrical subcontractor include
these costs in their bid, the contractor has a negotiating
advantage.17–3 Separate Contracts
The electrical contractor does the takeoff and bidding, but
this does not mean that the estimator for general construc-
tion should not review the drawings and specifications for
this work. Often, when projects are being bid under sepa-
rate contracts, the contractors for each phase receive the
drawings only for that phase (or portion of work) on which
they will be bidding. (The bidders for general construction
may receive no electrical or mechanical plans.) In this case,
a trip to the plan room or to the office of the electrical,
HVAC, and plumbing contractors who are bidding the pro-
ject should be made so that the drawings and specifications
may be investigated.
Even under separate contracts, there are many areas of
mutual responsibility and coordination. Keep in mind that
the entire building must fit together and operate as one unit.
The major areas of coordination for single and separate con-
tracts are outlined in Section 17–4. If separate contracts are
being used, the contractor needs to be aware of who is pro-
viding the temporary wiring and lighting.17–4 Coordination Requirements
Figure 17.2 lists the major areas of coordination required
between the electrical and general contractors.
Coordination of work among the electrical, HVAC, and
plumbing contractors themselves is also important, since
the electrical, HVAC, and plumbing contractors may all
have work to do on a particular piece of equipment. For
example, the HVAC contractor may install the boiler unit in
place, the electrical contractor may make all power connec-
tions, and the plumbing contractor may connect the water
lines. There are many instances of several trades connecting
to one item. Coordination and an understanding of the
work to be performed by each contractor are important to a
smooth-running job.17–5 Checklist
Rough:
conduit (sizes and lengths)
wire (type, sizes, and lengths)
outlets (floor, wall, overhead)
switches (2-, 3-, and 4-way)
panel boards
breakers (size, number of each)
outlets, weatherproof
control panels
power requirementsElectrical 215