The cistern water is supplied to the bath-room, and to the hot-water reservoir, by means of a tank placed in the attic, or at least above the highest fixture. It sometimes happens that the supply pipe from the tank above the attic floor freezes. All this may be prevented by enclosing the tank, and the pipe which connects with it, with a large box or canvas covering which is six or eight inches larger than the tank. This confines the warm air from the duct mentioned, so that as long as there is heat it will always be in this enclosure.
The outside drain, which connects with the vault or sewer, is, in some instances, trapped previous to its entrance to the sewer or vault. In such cases, this trap should have a connection with the outer air, and on the side of the trap towards the house. Sometimes this outer-air connection is made into the water spout from the roof; but this is not proper, for the reason that the sewer gas, or the gas from the vault, is almost certain to destroy the spout. Again, this spout may come out near a dormer, or may pass near a window, and in either case may contaminate the air in the house. It is better that this ventilating connection should be in the yard, at some distance from the house, or, better yet, that there should be a long iron pipe extending well above the ground. It should be understood that this vent has no direct connection with the sewer, but merely with the soil pipe and drain back of the trap; with that part of it which is nearest to, and in, the house.
Sometimes it is necessary to run the down spouts into the sewer connection; in such a case one should be certain that the down-spout openings are not near the dormers, and that they have no connection whatever with the cistern. It is common to have a switch or cut-off in the down spout, so that the latter may be connected either with the cistern or sewer. This is very bad practice. While it is connected with the sewer or with the drain pipe, the down spout is contaminated with all the foulness of the air of the drain. On its being connected with the cistern, the water is poisoned.
Immunity from sewer gas in the house is largely dependent upon the flushing and ventilation of the drain and the soil pipe. In the case of a drain which is trapped as described, there is an air connection through the vent before the trap; then the soil pipe which is in the house should continue upward through the roof. Thus there is a fresh air inlet through the drain, and upward through the soil pipe of the house. Such a connection prevents the possibility of siphoning the traps, as it gives an outward air connection. The water passing through the drain or soil pipe can draw its supply of air from the upward soil vent, rather than through the traps which contain water. When there is no upward vent of the soil or drain, the water in the traps which connect therewith will be drawn out by the passage of water through the drain where fixtures are used.
There are those who maintain that there should be no trap in the yard or adjacent to the house, but that there should be a straight run from the soil pipe to the sewer or vault, and upward through the roof and above the house. It is good practice to use the trap as described for sewer connections, but not for open vault connections.
A grease sink is frequently placed in the drain to intercept the passage of grease into the vault. It is so placed and connected that only the water from the kitchen sink, or other fixtures where the water contains grease, may enter it. It is made of brick, and is usually of six or eight barrels capacity. A four-inch pipe connects it with the kitchen waste, and if the grease sink is placed adjacent to the main drain, there can be a similar connection between it and the main drain. It should be a siphon connection, so that the sink will become nearly full before it discharges. When it discharges through the siphon the water will go out with a rush and leave the grease in the sink. This makes an intermittent discharge into the main drain, which flushes or cleanses it thoroughly and is much better than a constant small flow of water. This grease sink must be cleaned from time to time. Small cast-iron grease sinks are sometimes placed under kitchen sinks in very large dwellings or hotels.
Nothing particular need be said in regard to wash-stands more than has been said, excepting, possibly, that the drain should be trapped, ventilated, and connected with the soil pipe; also that there should be a lead safe or safety pan on the floor under the wash-stand when they are enclosed; it is preferable that they should remain unenclosed. It has been common to connect this safe with the soil pipe. It is only intended that it should be useful in cases of accidental overflow; but, notwithstanding the fact that there be a trap in the safe waste or drain, it would be empty most of the time, because of the evaporation of the water. It is proper to make direct connection with the cellar or kitchen sink.
The bath-tub should have the same-sized drain connection as the wash-stand; that is, one and one-half inch in diameter, trapped. The overflows from both the wash-stand and tub should be flushed with hot water quite frequently, to avoid the soap smells which are so common to bath-rooms. It often happens that those who have bath-rooms in their houses imagine that they smell sewer gas, when it is nothing more or less than the smell of rancid soap.