Whenever a branch line of soil or waste pipe is extended 15 feet or more from the main soil or waste stack into which it is connected, the branch should be carried through the roof.

Soil, waste, or vent pipe should ordinarily not be carried on the outside of any building. Such a prohibition is imperative in a cold climate, but there is not so much to be said against it when practiced in a warm climate, where there is no trouble from frost to be feared. When a building adjoins another of greater height having doors or windows overlooking the lower building, the openings of all roof pipes coming through the roof of the lower building should be at least 12 feet from windows and doors in the higher building, and no roof pipe should be closer than 6 feet to any chimney opening. It is quite customary to use a wire basket or other protector to cover the open end of a roof pipe, but there is something to be said against the practice. The meshes of the basket being somewhat close together furnish opportunity for the collection of frost over the basket in cold weather, resulting in the entire or partial stoppage of the vent opening. The practice, however, would not be open to objection in warm climates and would act as a protection against the entrance through the roof pipe of leaves, etc.

The roof connection is made in a variety of ways, either with sheet lead or with patented roof flanges. In Figs. 95 to 100 are shown several of these connections. Fig. 95 shows a device that is, perhaps, used more extensively than others. It consists of a cast-iron hub riveted to a copper flange, the latter being nailed to the roof as shown.

The roof flange of Fig. 96 is also a patented device, consisting of a lead body attached to a copper flange, having at its upper end an iron ring into which a lead ring is calked. The use of the soft lead ring obviates the necessity of carrying a pot of molten metal to the roof with which to make the lead joint. Fig. 97 shows a flange which may be used on roofs of any pitch, the joint being made by a rubber ring which encircles the pipe. Unless the surface of the pipe is smooth, the rubber is not liable to make perfect contact around the entire circumference, in which Case leakage of water down the outside of the pipe will follow. Moreover, the life of rubber is not of long duration, when exposed to the air and weather, and soon loses its elasticity. Fig. 98 shows a method often followed by the workman in making his own roof flange, as does Fig. 100 also. In Fig. 98 the sheet lead is flanged over and down into the hub. When the lead joint is poured and calked, a very satisfactory piece of work results. In Fig. 100 the sheet lead forms an upright collar around the pipe, and after the joint is poured and calked the end of the collar is rounded over as shown. Fig. 99 shows a very satisfactory roof flange, in the use of which leakage of roof water down the pipe is an impossibility. A very popular feature of this device is the fact that no lead joint has to be poured and calked on the roof. This is a point much appreciated by the workman, as it is often difficult, particularly on steep roofs, to melt and pour the metal for a calked joint. The copper collar fitting up into this device is loose, being held rigidly only at the roof. Consequently, the settling of the roof does not tear away any part of the connection and result in leakage. In several of the illustrations various reducing fittings are to be seen.

Figs. 95 100.   Roof Connections.

Figs. 95-100. - Roof Connections.

Fig. 101.   Connections between Lead , Wrought  and Cast iron Pipes.

Fig. 101. - Connections between Lead-, Wrought- and Cast-iron Pipes.

Plumbing ordinances lay down special rules for the making of connections between different kinds of pipe. In Fig. 101 are to be seen the common connections, and other connections will be shown later on, in the consideration of special subjects, such as the Durham system. Lead pipe is connected to cast-iron pipe by means of a brass ferrule, to which the lead pipe is connected by a wiped joint, the ferrule being calked into the pipe. One of the figures shown illustrates the lead bend connected in the same way. Lead pipe is connected to wrought-iron pipe by means of a brass soldering nipple. One end of the nipple is threaded and screws into the fitting on the wrought-iron pipe, the lead pipe connecting with the other end by means of a wiped joint. Sometimes in place of the wiped joint a cup joint or an overcast joint is used. The cup joint is made by swelling out the end of the lead pipe, dropping the pipe, ferrule, or nipple into the bell end thus formed, and with a soldering copper the two are soldered together. The overcast joint is made by the use of a soldering copper, the solder being formed around the joint in the form of a wiped joint, and then smoothed over with a rasp or file to give it the smoothness and symmetry of a wiped joint;

Neither of these joints is allowed by plumbing ordinances, although they are used to a large extent in sections that are not under plumbing restrictions. The wiped joint is much stronger and more perfect than either the cup or overcast joint.

Wrought-iron pipe is connected to cast-iron pipe by means of tapped fittings, into which the wrought-iron pipe may be screwed. Wrought iron is also sometimes calked into the hubs of cast-iron pipe if the sizes happen to come right. If not, a coupling screwed onto the end of the wrought-iron pipe will often allow it to be calked.