This section is from the book "The Building Trades Pocketbook", by International Correspondence Schools. Also available from Amazon: Building Trades Pocketbook: a Handy Manual of reference on Building Construction.
1. General water-closet accommodation should never be placed in cellar or basement, but should be located where plenty of daylight and ventilation can be obtained, and should open to the outer atmosphere either direct, or by air-shafts at least 3 ft. square.
2. To prevent damp cellars, subsoil drains should be employed where necessary. They must be effectively trapped from sewers or house drains, and some means must be employed to maintain a seal. A check-valve, or back-water trap should be used to prevent a back discharge of sewage into them, should the drains become choked.
3. The arrangement of all drainage or vent pipes should be as direct as possible.
4. If there is a sewer in a street, every building should connect to it separately.
5. Where the soil is natural, the house sewer may be of vitrified earthenware pipe, uniformly bedded and jointed with Portland cement and clean sharp sand. This pipe must run straight, and must have a clear bore.
6. If the soil is filled in or made, the house sewer must be of extra-heavy cast iron, asphalt-coated; of wrought iron, galvanized, and asphalt-coated; or of brass pipes, to avoid leakage by a settlement of the earth.
7. When it is necessary to run a private sewer to connect with a sewer in another street, it should be laid outside the curb of the street which the buildings face, not across lots where buildings may in future be erected.
8. The main house drains should be run above the cellar floor when possible, and be secured against the cellar walls, supported upon piers built under each joint, or suspended from the cellar ceiling by adjustable hangers.
10. All changes in direction should be made with curved pipes or Y branches and 1/16 or 1/8 bends.
11. Old sewers should never be employed for new buildings unless first examined and tested by the smoke machine.
12. All house-drainage systems should be disconnected from city sewers by means of a main disconnect-ing trap, as shown in Fig. 1.
If the sewage from a country building delivers into a sea, a river, or open space, the main drain trap may often be advantageously omitted. A fresh-air inlet must always accompany a main drain trap.
15. Vent pipes above roofs must be 4 in. in diameter or larger, and no cowls or vent caps should be used.
16. Vent pipes passing up through a low roof, and within 30 ft. of any windows in taller adjoining buildings, should be extended to safe points above the higher roofs.
17. All drain, soil, waste, and vent pipes between the main disconnecting trap and the vent outlets must be clear and unobstructed by traps, check-valves, etc.
18. All house-drainage work should be as accessible as possible, being placed either on the faces of walls or in air-shafts. When placed in walls they should be covered by movable pipe boards.
19. Every fixture in a building must be separately trapped close to each fixture, except where a sink and washtubs adjoin each other, in which case the waste pipe from the tubs may join the inlet side of the sink trap below the water seal.
20. All fixture and other such traps in a building must be back-vented by a separate pipe which may deliver into a special back-vent stack at a point about 2 or 3 in. below top of fixture, for tenement or apartment buildings, and at much higher points, if desired, for private-residence work, but in no case at points lower than bottoms of fixtures or bowls.
21. Where lead-waste or back-vent branches connect to cast-iron stacks, the connections must be made with heavy brass ferrules and wiped solder joints; if to wrought-iron or brass stacks, by means of brass-screwed solder nipples provided with a socket to receive the lead pipe and form a flush internal surface. All solder joints in a plumbing system should be "wiped."
22. Special precaution should be taken to secure perfect joints between water-closet traps placed above the floor and the branch soil and vent pipes for same. Brass floor plates should be used for the floor connections. A smoke test is necessary to prove these joints. Back-vent horn or porcelain traps should not be permitted, as they soon break off. The best modern practice is to back-vent the soil-pipe waste close to the floor connection by means of a wiped or screwed joint.
23. Overflow pipes from all fixtures must connect to traps on house side of their seals.
24. All fixture safes should be properly graded to a special waste pipe which must deliver openly at some point, such as a safe-waste sink in the cellar. The outlets of these pipes should be covered with light flap valves.
25. The sediment pipe from the kitchen boilers should not be connected on the outlet side of the sink or other trap.
26. A separate small tank or cistern should be employed to flush every water closet, and in no case should any water closet or urinal be supplied directly from the street pressure pipes when there is any liability of a drawback in the street mains.
27. One water closet, at least, should be allowed for fifteen inmates of a building. Every story of a tenement should contain at least one water closet.
28. Drinking Mater should be drawn directly from the street mains. Tank water may be used for washing and bathing purposes.
29. House tanks should be made of wood, and if placed inside the building should be lined with tinned and planished sheet copper.
30. Outside tanks may be circular and made of cedar staves or wrought iron. Overflow from such tanks should discharge on the roof.
31. Overflow pipes from inside tanks may deliver into an eaves gutter if available, or may be trapped and discharge into an open sink. No pipe connecting to a tank should deliver directly into the drainage system.
32. All rain-water leaders, area water boxes, and subsoil drains, must be trapped from the drainage system, and the seals maintained.
33. In all cases where water comes muddy from the mains, a straining filter should be located in the cellar, to filter all water in the building; muddy water clogs boilers, water-backs, and circulation pipes.
34. A special germ-proof filter is a very valuable addition, and should be placed at a convenient point, to supply water for drinking purposes.
35. Steam-exhaust, blow-off, or drip pipes should not deliver directly into a drainage system. Such water should deliver through a deep seal trap, and at a temperature not higher than 100° F.
36. No privy vaults or cesspools for sewage should be per-mitted in any place where water closets can be connected with a city sewer.
37. All privy vaults and cesspools should be frequently treated with small quantities of disinfectant, and should be cleaned out thoroughly and often.
38. All architects should see that every drainage system, when completed, is tested with smoke under a pressure of at
1 inch water column, because the sanitary arrangements are seldom perfect when this final test is neglected.