Laying the Pipe.—The drain pipe should be handled with care, for it is easily broken. The trench should be laid out and dug, then the pipe can be laid in it with a grade toward the outlet or discharge. If pipes with a hub on one end are used, the hub should not be cemented. A little oakum is packed in the hub to steady the pipe and keep sand out, the bottom of joint is cemented, a piece of tar paper can be laid over the top of the joint to keep the sand out. With joints made this way, the water can find its way to the bore of the pipe and yet the sand will be kept out of the pipe. As soon as the water gets into the bore of the pipe it has a clear passageway to some discharge point away from the building. If tile pipes without any hubs are used, some covering should be put around the joint to keep out the sand and still allow the water to find its way into the pipes.
Discharge of Sub-soil Drain.—The water that accumulates in a sub-soil drain must be carried off to some point away from the building. As the pipes are generally under the cellar bottom and under the house drain, it is very evident that this drain cannot discharge into the house drain sewer, directly. If the building site is on a hill, the drain can be carried out and discharged on the surface at a point that is somewhat lower than the level of the pipe under the building. Where this cannot be done, it will be necessary to have the different lines of pipes discharge into a pit. The water is accumulated in this pit until it is filled, then it will automatically empty itself as later explained.
Pit Construction.—The pit for the sub-soil water is constructed of cement. A pit 2 feet square or 2 feet in diameter and 3 feet deep will answer all requirements. A pit of this depth will allow a pitch for all lines of pipe, and is large enough for ordinary installations. The pit is built up to the surface of the cemented floor of the basement and covered with a removable iron cover.
Cellar Drainer or Pump.—A cellar drainer is employed to empty the above-mentioned pit. The cellar drainer works automatically. When the pit is filled with water, the drainer operates and empties the pit and discharges the water into a sink or open sewer connection. When the pit is emptied, the drainer shuts off. The cellar drainer is operated by water pressure. When the valve is opened, a small jet of water is discharged into a larger pipe. The velocity of this small jet of water creates a suction and carries along with it some of the water in the pit. This suction continues until the tank is empty. There should always be a strainer on the suction pipe, also on the supply pipe, to prevent any particles of dirt getting into the valve. The pipes leading to and from the drainer should empty into an open sink where it can be seen. There is a possibility of the drainer valve leaking and then the water pressure will leak through it, causing a waste of water. If this leakage can be seen where it discharges, then the trouble can be rectified. The cellar drainer is connected directly with the water pressure and should have a valve close to the connection to control the supply.
CHAPTER IX
Storm and Sanitary Drainage with Sewage Disposal
in View
The accompanying drawing of storm and sanitary drains should be studied in detail by the reader. The location of each trap and fitting should be studied carefully and the reason that it is put in that particular place should be thoroughly understood. Below, each plan has been taken and gone over in detail, bringing out the reasons for fittings and traps, also the arrangement of the piping.