Replacing finished surfaces after plumbing (especially patching walls) usually takes several days. Repairing a large wall patch (or even replacing an entire wall) takes only a little more time than a small patch, so open plenty of space for working. Once you’ve opened the vent and drain lines, running the supplies, which will usually run alongside drain-waste-vent (DWV) lines, will be relatively easy. Before you begin, brush up on your basic carpentry skills, understand your home’s structure, and make sure you know how to install pipe. It’s also a good idea to get your plan approved by the local building department to make sure it adheres to plumbing codes.
How to Stabilize and Protect Pipes
Whenever possible, run pipes through holes in the center of framing members. To keep pipes from rattling, line the holes with felt or use wood shims. Slip a shim under the pipe and tap in until it is firmly in place, but not tight, to allow for expansion. If notches are needed, make them as small as possible, as they weaken the framing member. You can also use metal plates to protect pipes from nails. Running drainpipe through joists calls for meticulous work. The holes must follow a straight line across the floor and must ascend or descend so the pipe will be sloped ¼ inch per foot. (If joists are 16 inches on center and pipes run across them at a right angle, holes should differ in height by about ⅜ inch.) Vent pipes might run level, although some codes call for a slight slope toward the main drain. All drain lines must be sloped. For a precise slope, strike a level line on the studs and measure down ¼-inch per running foot. Note that codes might also call for fireproof caulking in walls.
Tips for Running Pipe Through a Floor
Running drainpipe through joists calls for meticulous work. The holes must follow a straight line across the floor and must ascend or descend so the pipe will be sloped ¼ inch per foot. (If joists are 16 inches on center and pipes run across them at a right angle, holes should differ in height by about ⅜ inch.)
Tips for Running Pipe Through a Wall
Vent pipes might run level, although some codes call for a slight slope toward the main drain. All drain lines must be sloped. For a precise slope, strike a level line on the studs and measure down ¼-inch per running foot. Note that codes might also call for fireproof caulking in walls.
