above the concrete floor. This arrangement provides more flexibility to modify the location of the standpipe at some future date however, the standpipe must be secured to the wall or other- wise supported. Another alternative is to connect the standpipe to the 2″ horizontal drainpipe below the concrete floor using a 2 × 2 × 1½ wye. This type of installation provides more support for the standpipe and permits the cleanout to be installed below the sanitary tee that connects the laundry tub to the stack. The sketch shows P-traps at the laundry tub and kitchen sink. These P-traps will not be installed until the fixtures are put in place. Short lengths of horizontal pipe (stub-outs) must be installed and capped during the rough-in stage. During the finish stage, these stub-outs will be cut off and trap adapters installed so the P-trap can be joined to the fixture. Note that two fittings are needed at locations F and G. At the two F locations, a cap is needed so that the stub-outs can be capped for testing. The G location requires a bushing to reduce the 2″ opening at the top of the test tee to receive the 1½″ vertical drain/vent pipe. This stack must fit inside the exterior wall cavity in the kitchen. This makes it necessary to install two 45° ells near the top of the concrete foundation wall so the stack can be offset into the wall cavity. One 45° ell, combined with rotating the 90° ell by 45°, will allow the sink drain to make the same 45° offset. Figure 19-6 shows the pipe and fittings for the lower portion of the stack. Once enough digging has been done to install the 2″ long radius 90° ell, work can begin on the stack. If the standpipe is installed as shown in the drawing, the P-trap should be near the concrete floor once it is poured. Given this and knowing where the top of the finished floor will be makes it possible to locate the sanitary tee for the standpipe. Begin by determining the distance from the bottom of the P-trap to the centerline of its outlet. Also, measure the distance from the bottom of the sanitary tee to the centerline of its inlet, Figure 19-7A. For this example, assume that distance A is 4⅝″ and B is 3⅝″. Since the P-trap is to rest on top of the concrete floor, the centerline outlet of the P-trap must be 8⅝″ above the footing (4⅝″ + 4″). Measure and mark this location on the foundation wall, Figure 19-7B. Calculate the total fall for the 2′6″ length of pipe that will join the P-trap and sanitary tee, Figure 19-7C. The total fall for the 2′6″ pipe is ⅝ ″. Installing a Stack While the trenches are being dug, work can begin on the stacks. First, consider the kitchen/ laundry DWV piping. Figure 19-5 provides a sketch of this pipe and fittings to be used. The names and dimensions of the fittings are given in the table included with the sketch. The sketch shows the standpipe for a clothes washer installed Goodheart-Willcox Publisher Figure 19-5. Schematic drawing for laundry/kitchen stack. Table identifies the fittings needed. Label Quantity Description A B C D E F F G G H I J 1 1 1 2 1 3 2 1 1 1 2 1 2″ floor drain 2 × 2 × 2 wye 2″ long-radius 90° ell 2 × 2 × 1½ san. tee 1½″ P-trap 1½″ 90° ell 1½″ trap adapters 2″ test tee w/ cleanout plug 2 × 1½ bushing 2 × 1½ × 1½ san. tee 2″ 45° ells 1½″ 45° ell A B D C E F H D G To 3 × 3 × 2 wye F I F J 2″ 11⁄2″ 11⁄2″ 11⁄2″ 2″ 2″ 11⁄2″ 2″ Chapter 19 DWV Pipe and Fitting Installation 301 Copyright Goodheart-Willcox Co., Inc.