In fitting up the plumbing in apartment houses, or in designing the layout and writing the specifications, one special provision is necessary that is not of so much importance in residence work. This special requirement is the providing of overflow pipes for each fixture or set of fixtures, particularly if the fixtures are provided with stoppers. Take a set of laundry trays, for instance. If clothes were put to soak over night, and one of the faucets did not shut off tight, the fixtures would fill and overflow, perhaps creating considerable damage to the ceilings below, and at all events causing quite a nuisance to tenants on lower floors. For this reason, it is customary to require laundry trays fitted with overflow pipes, and in some cases the kitchen sinks are likewise required to be fitted with overflows.
Unless the water supply in the city where an apartment house is to be built is perfectly pure and wholesome, a sanitary filter should form part of the plumbing equipment to sterilize the water before delivering it to the tenants. Meters will likewise generally be required, and should be kept in mind by the designer, because either the owner will consider it cheaper to buy water by meter rates or the Water Board will insist on the building being metered, so that almost invariably a meter will be required. Sometimes water will not reach to the upper floor of an apartment house and a house tank must be provided. This in turn necessitates the installation of a pump for filling the tank, and the designer must keep in mind the various pumps at his choice, such as hot-air pumps, electric operated pumps or steam pumps, the conditions governing the case determining the choice.
Fig. 88 Fourth Floor Plan of Apartment House
Yard and area drains must not be forgotten, nor leader pipes when they are permitted to discharge into the sewer. Likewise a trapped and water supplied sink is generally required in the basement to take the drip from the ice boxes.