Essentials of Plumbing Lesson

INSTALLING SEWER PIPELINES

When a building foundation is under construction, the building sewer pipeline is installed in the ground. First, a hole is cut in the main sewer line. Then a fitting is attached to the main sewer line. Finally the building sewer pipeline is laid, supported, and connected at the correct grade slope.

Connecting the Building Sewer Pipeline to the Main Sewer Pipeline

Cutting the hole in the main sewer pipeline. Cut a hole in the main sewer pipeline above the normal sewerage flow level. Use the following steps:

Place the fitting on the sewer pipeline where the fitting will be installed. Trace around the fitting with a crayon or chalk. This tracing marks where the hole will be cut.
With a hammer and cold chisel, score the mark to a depth of 1/8 inch.
Knock a hole in the center of the scored area with the hammer.
Starting from the hole and working outward to the scored mark, tap lightly with the hammer to widen the hole.
Continue until the hole is the correct size.

Cutting the hole in the main sewer pipeline.

Installing the thimble. The thimble is the fitting that connects the main sewer pipeline to the building sewer pipeline. To install the thimble on the main sewer pipeline, use the following steps:

Place the thimble over the made-to-fit hole on the main sewer pipeline.
Support the thimble in place with pieces of scrap lumber.
Pack the connection with oakum and seal it with a portland cement mixture.
Do not remove the support until the joint sets.

Installing the thimble.

Laying the building sewer pipeline. Normally, cast-iron soil pipe is used for sewer pipelines. To install the building sewer pipeline, use the following steps:

Place the piping in a dug-out trench, one length at a time. Start at the sewer thimble and work toward the building.
Set the pipe to a grade slope of ¼ inch per foot with a carpenter's level.
Support the pipe to maintain the grade slope.
After all the pipes are set, make the joint connections.

Laying the building sewer pipeline.