This section is from the book "A Treatise On Architecture And Building Construction Vol4: Plumbing And Gas-Fitting, Heating And Ventilation, Painting And Decorating, Estimating And Calculating Quantities", by The Colliery Engineer Co. Also available from Amazon: A Treatise On Architecture And Building Construction.
51. An approximate figure for cost of plumbing is 10 per cent. of the cost of the building. This figure is for good materials and labor, and, of course, is subject to considerable variation. The cost of labor alone will average about one-fourth the cost of the materials.
Drainage System. Measure all horizontal pipes from the plans, and vertical pipes from the sectional drawings.
Itemize the several pipes in the different kinds and classes.
Estimate all earthen pipe by the lineal foot, allowing for Portland cement in the joints.
Estimate all cast-iron pipe by the lineal foot, allowing for each joint 3/4 pound of lead for every inch in diameter of the pipe.
Estimate wrought-iron pipe by the lineal foot, inclusive of couplings.
Estimate brass, copper, and lead pipe by the pound.
Estimate all traps, bends, branches, increasers, reducers, and other fittings separately, except such special brass fixtures, traps, and connections as are included in the cost of the fixtures. Do not figure lead bends which are smaller than 2 inches.
Estimate on brass-ferrule connections at all points where lead pipe joins iron pipe.
Estimate on all solder joints (wiped), allowing 1 pound of solder for every inch inside diameter of the pipe.
Water-Supply System. For street supply, allow for permits, corporation tapping, and curb box.
Measure the service pipe from street main to cellar, and allow for a stop and waste cock, inside the cellar wall.
Measure all horizontal distributing pipes from the plans, and all vertical distributing pipes from the sectional drawings.
Measure all branches for the several fixtures on the different floors, to the lawn hydrants, etc.
Itemize the different kinds and classes of pipes.
Estimate lead, brass, and copper water pipes by the pound, and wrought-iron water pipe by the lineal foot.
Itemize all stop-cocks, pipe tacks, straps, hangers, etc. separately.
Estimate all water-pipe fittings less than 1 1/2 inches by the pound.
Figure on brass solder-nipple connections in all places where lead pipes join iron pipes.
Estimate on kitchen boiler, sediment cock, and range connections; and also faucets for all fixtures other than those which are included in the costs of the fixtures.
Estimate upon garden hydrants and lawn sprinklers, and allow a stop and waste cock in cellar for each.
Well Supply. Figure on double-action force pump in kitchen or laundry, if well is not deeper than 26 feet below the pump; for a deep well, estimate on pumping engine or windmill.
Measure lead tank linings in square feet, and estimate by the pound, allowing 1 pound of solder for every 2 feet of seams.
Allow 2 feet of lead pipe to connect iron pipes to house tank, and for stop-cocks close to tank.
Provide for telltale and overflow pipes for tank.
Estimate copper tanks in square feet and by the pound, allowing 1 pound for each square foot.
If there are iron, slate, glass, or cedar tanks, figure them separately.
Fixtures. Estimate each fixture separately, and include traps, faucets, waste, vent, and water connections to walls or floors. When the sewer is long and has but little fall, figure on using a grease trap for the kitchen sink.