The work of plumbing has a direct result on the health of the occupants of buildings; therefore in order that the plumbing may not be installed improperly and impair the health of the occupants, it is necessary to provide a code governing the installation of plumbing. Naturally these laws at first were under the control of the health department of cities, but of late years the building departments have assumed control of the codes with the result that coöperation with the building codes is now the practice rather than the exception.

To make certain the carrying out of the plumbing codes, it is required that a plan indicating the run, size, and length of pipes, location and number of fixtures of the prospective job be filed in the building department of the city, before the work is started. If the plan is approved by the plumbing inspector and acceptance is sent, then the work can be started. After a job is completed a test is made and the job is inspected by the plumbing inspector, and if found to meet requirements a written acceptance of the work is given by the building department. An effort is being made throughout the country to have the plumbing codes under State control rather than have a number of different codes in as many different cities and towns. The State code can be so arranged that it will apply to either city or town.

The installation of plumbing varies in different States. In the northern part of the United States all pipes which pass through the roof, if less than 4-inch must be increased to 4-inch. A pipe smaller than 4-inch will be filled with hoar frost during the winter and render the pipe useless to perform its function as a vent pipe. Pipes laid under ground in the Northern States must be at least 4 feet below the surface to protect them from freezing. In the Southern States the frost does not penetrate the ground to such a distance and the pipes can be laid on the surface.

Following is a State or City plumbing code insofar as it relates to the actual installation of plumbing.

Sec. 1. Plans and Specifications. - There shall be a separate plan for each building, public or private, or any addition thereto, or alterations thereof, accompanied by specifications showing the location, size and kind of pipe, traps, closets and fixtures to be used, which plans and specifications shall be filed with the board or bureau of buildings. The said plans and specifications shall be furnished by the architect, plumber or owner, and filed by the plumber. All applications for change in plans must be made in writing.

Sec. 2. Filing Plans and Specifications. - Plumbers before commencing the construction of plumbing work in any building (except in case of repairs, which are here defined to relate to the mending of leaks in soil, vent, or waste pipes, faucets, valves and water-supply pipes, and shall not be construed to admit of the replacing of any fixture, such as water closets, bath tubs, lavatories, sinks, etc., or the respective traps for such fixtures) shall submit to the bureau plans and specifications, legibly drawn in ink, on blanks to be furnished by said board or bureau. Where two or more buildings are located together and on the same street, and the plumbing work is identical in each, one plan will be sufficient. Plans will be approved or rejected within 24 hours after their receipt.

Sec. 3. Material of House Drain and Sewer. - House drains or soil pipes laid beneath floor must be extra heavy cast-iron pipe, with leaded and caulked joints, and carried 5 feet outside cellar wall. All drains and soil pipes connected with main drain where it is above the cellar floor shall be extra heavy cast-iron pipe with leaded joints properly secured or of heavy wrought-iron pipe with screw joints properly secured and carried 5 feet outside cellar wall and all arrangements for soil and waste pipes shall be run as direct as possible. Changes of direction on pipes shall be made with "Y"-branches, both above and below the ground, and where such pipes pass through a new foundation-wall a relieving arch shall be built over it, with a 2-inch space on either side of the pipe.

Sec. 4. - The size of main house drain shall be determined by the total area of the buildings and paved surfaces to be drained, according to the following table, if iron pipe is used. If the pipe is terra-cotta the pipe shall be one size larger than for the same amount of area drainage.

DiameterFall 1⁄4 inch per footFall 1⁄2 inch per foot
4 inches.....1,800 square feet drainage2,500 square feet drainage area
5 inches.....3,000 square feet drainage4,500 square feet drainage area
6 inches.....5,000 square feet drainage7,500 square feet drainage area
8 inches.....9,100 square feet drainage13,600 square feet drainage area
10 inches.....14,000 square feet drainage20,000 square feet drainage area

The main house drains may be decreased in diameter beyond the rain-water conductor or surface inlet by permission of the bureau, when the plans show that the conditions are such as to warrant such decrease, but in no case shall the main house drain be less than 4 inches in diameter.

Sec. 5. Main Trap. - An iron running trap with two clean-outs must be placed in the house drain near the front wall of the house, and on the sewer side of all connections. If placed outside the house or below the cellar floor the clean-outs must extend to surface with brass screw cap ferrules caulked in. If outside the house, it must never be placed less than 4 feet below the surface of the ground.

Sec. 6. Fresh-air Inlet. - A fresh-air inlet pipe must be connected with the house drain just inside of the house trap and extended to the outer air, terminating with a return bend, or a vent cap or a grating with an open end 1 foot above grade at the most available point to be determined by the building department.

The fresh-air inlet pipe must be 4 inches in diameter for house drains of 6 inches or less and as much larger as the building department may direct for house drains more than 6 inches in diameter.

Sec. 7. Laying of House Sewers and Drains. - House sewers and house drains must, where possible, be given an even grade to the main sewer of not less than 1⁄4 inch to the foot. Full-sized "Y"- and "T"-branch fittings for handhole clean-outs must be provided where required on house drain and its branches. No clean-out need be larger than 6 inches.