Overview of DWV Installation The preparatory work described in Chapter 18 provides an overall understanding of the DWV system. Based on this understanding, it is possible to carry out the installation in an efficient manner. Make sure you understand the general plan for the DWV system. For example, the sketch in Figure 19-3 shows the DWV system for a one-story house with laundry facilities in the basement and two bathrooms and a kitchen on the main floor. The fixtures to be installed and the size of the DWV piping are noted on the sketch. As you read the rest of this section, refer to Figure 19-3 to keep the overall installation in perspective. This installation requires two stacks that extend through the roof. The horizontal runs from these stacks will join below the basement floor and connect to the building sewer near the point where it enters the building. Note that a floor drain is to be connected to the horizontal drain- pipe going to the kitchen/laundry stack. It may be helpful to think of the installation in three sections: First, the horizontal runs below the basement floor. Second, the DWV piping for the bathrooms. Finally, the DWV piping for the kitchen and laundry areas. If more than one plumber is working on the job, the work could be divided among the crew members on this basis. Assuming that the openings have already been cut and the needed structural modifications completed, put a length of the correct-size DWV pipe through the openings in the floor for each of the stacks and extend the pipe to the basement floor. Working from the basement, plumb the stacks to locate one end of the horizontal drain/waste pipe to be installed below the basement floor. An alternative is to suspend a plumb bob through the center of the opening in the sanitary tee to the top Floor drain Sink Lav. Lav. Tub Tub W.C. W.C. 11⁄2″ 11⁄2″ 11⁄4″ 11⁄4″ 21⁄2″ 2″ 3″ 21⁄2″ 3″ 3″ 2″ 11⁄2″ 11⁄2″ 11⁄2″ 2″ 2″ 4″ To Building Sewer Laundry tub Standpipe Goodheart-Willcox Publisher Figure 19-3. Schematic drawing of the DWV piping for a house with two bathrooms. Chapter 19 DWV Pipe and Fitting Installation 299 Copyright Goodheart-Willcox Co., Inc.