Begin laying the pipe at the tank with the bell end uphill. Joints in clay-tile pipe are commonly made with portland cement mortar or grout. Where root-proof joints are essential, sulfur-sand compounds may be used or copper rings provided and used with cement-mortar joints. Asphalt-mastic compounds, however, are more satisfactory. For cast-iron soil pipe, lead is the standard joint material.
After the hub is pushed into the bell, oakum (or old hemp rope) is packed with a calking iron or a piece of wood ([fig. 3], A.) solidly and evenly in the joint to a depth of about half an inch to center the hub end in the bell and to keep the joint filler from getting inside the pipe. Oil, grease, or dirt on the joint surfaces should be removed, as it will prevent joint material from sticking. [Figure 3] shows the different jointing methods.
Figure 2.—Establishing grade for sewer. A, 2- by 4-inch stakes are set each side of the trench at convenient distances a, b, c, and d. Then a board is nailed horizontally on the stakes at d at a convenient height above the bottom of the trench, that is, the bottom of the sewer leaving the house. A board is nailed likewise to the stakes at a the same height above the inlet to the tank that d is above the bottom of the trench. Similarly, boards are set at b and c by sighting from a to d so the tops of the intermediate boards will be in line. B, The exact grade of the sewer is obtained by measuring from the grade cord with the 1- by 1-inch stick, shown in detail. The length of the stick must equal the height of the board above sewer at d.
Bituminous, sulfur-sand, lead, and other commercial joint compounds are poured while hot into the joint from a ladle ([fig. 3], F), and when the work is well done they form a joint that is practically root-proof. They are more expensive than cement mortar.
For molding hot compounds, a clay dike, or funnel, built about 3 inches high around the triangular opening at the top of the jointer greatly aids in the rapid and complete filling of the joint space. A hot joint must be poured continuously, otherwise a seam may develop between successive pourings.
Bituminous compounds make a slightly elastic joint. A joint in 4-inch pipe requires about 3/8 to 1/2 pound of compound and in 6-inch pipe about 1 to 11/2 pounds.
Sulfur-sand joints are hard and inelastic. The compound is made by mixing together equal volumes of ordinary powdered sulfur and very fine clean sand, preferably the finest quicksand, and then heating the mixture until the sulfur melts. A 4-inch joint takes about 3/4 pound and a 6-inch joint about 17/8 pounds of the mixture. Commercial sulfur-joint compounds also are available.