26 05 00 Common Work Results for Electrical
• Conduit should be taken off in three main categories− power distribution, branch power, and branch lighting−so the estimator can concentrate on systems and components, therefore making it easier to ensure all items have been accounted for.
• For cost modifications for elevated conduit installation, add the percentages to labor according to the height of installation, and only to the quantities exceeding the different height levels, not to the total conduit quantities.
• Remember that aluminum wiring of equal ampacity is larger in diameter than copper and may require larger conduit.
• If more than three wires at a time are being pulled, deduct percentages from the labor hours of that grouping of wires.
• The estimator should take the weights of materials into consideration when completing a takeoff. Topics to consider include: How will the materials be supported? What methods of support are available? How high will the support structure have to reach? Will the final support structure be able to withstand the total burden? Is the support material included or separate from the fixture, equipment, and material specified?
• Do not overlook the costs for equipment used in the installation. If scaffolding or highlifts are available in the field, contractors may use them in lieu of the proposed ladders and rolling staging.
26 20 00 Low-Voltage Electrical Transmission
• Supports and concrete pads may be shown on drawings for the larger equipment, or the support system may be only a piece of plywood for the back of a panelboard. In either case, it must be included in the costs.
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