Plumbing Installation Basics
A major plumbing project is a complicated affair that often requires demolition and carpentry skills. Bathroom or kitchen plumbing may be unusable for several days while completing the work, so make sure you have a backup bathroom or kitchen space to use during this time.div class="thumbnail">
Overview
![]()
A major plumbing project is a complicated affair that often requires demolition and carpentry skills. Bathroom or kitchen plumbing may be unusable for several days while completing the work, so make sure you have a backup bathroom or kitchen space to use during this time.
To ensure that your project goes quickly, always buy plenty of pipe and fittings—at least 25% more than you think you need. Making several extra trips to the building center is a nuisance and can add many hours to your project. Always purchase from a reputable retailer that will allow you to return leftover fittings for credit.
Pipe and fitting sizes, fixture layout, and pipe routing will always vary according to individual circumstances. When planning your project, carefully read all the information in the planning section. Before you begin work, create a detailed plumbing plan to guide your work and help you obtain the required permits.
From: The Complete Guide to Plumbing, 978-1-58923-378-2
Step 1
Installing New Plumbing
Use masking tape to mark the locations of fixtures and pipes on the walls and floors. Read the layout specifications that come with each sink, tub, or toilet, then mark the drain and supply lines accordingly. Position the fixtures on the floor, and outline them with tape. Measure and adjust until the arrangement is comfortable to you and meets minimum clearance specifications. If you are working in a finished room, prevent damage to wallpaper or paint by using self-adhesive notes to mark the walls.
Step 2
Installing New Plumbing
Consider the location of cabinets when roughing in the water supply and drain stub-outs. You may want to temporarily position the cabinets in their final locations before completing the drain and water supply runs.
Step 3
Installing New Plumbing
Install control valves at the points where the new branch supply lines meet the main distribution pipes. By installing valves, you can continue to supply the rest of the house with water while you are working on the new branches.Tip
2 x 4 loadbearing stud (1 7⁄16"diameter and 7⁄8" deep)
2 x 4 non-loadbearing stud (2 1⁄2" diameter and 1 7⁄16" deep)
2 x 6 loadbearing stud (2 1⁄4"diameter and 1 3⁄8" deep)
2 x 6 non-loadbearing stud (3 5⁄16"diameter and 2 3⁄16" deep)
2 x 6 joists (1 1⁄2"diameter and 7⁄8" deep)
2 x 8 joists (2 3⁄8"diameter and 1 1⁄4" deep)
2 x 10 joists (3 1⁄16"diameter and 1 1⁄2" deep)
2 x 12 joists (3 3⁄4" diameter and 1 7⁄8" deep)
Step 4
Installing New Plumbing
Create access panels so that in the future you will be able to service fixture fittings and shutoff valves located inside the walls. Frame an opening between studs, then trim the opening with wood moldings. Cover the opening with a removable plywood panel the same thickness as the wall surface, then finish it to match the surrounding walls.
Step 5
Installing New Plumbing
Protect pipes from punctures if they are less than 11⁄4" from the front face of wall studs or joists by attaching metal protector plates to the framing members.
Step 6
Installing New Plumbing
Test-fit materials before solvent-gluing or soldering joints. Test-fitting ensures that you have the correct fittings and enough pipe to do the job, and can help you avoid lengthy delays during installation.
Step 7
Installing New Plumbing
Support pipes adequately. Horizontal and vertical runs of DWV and water supply pipe must be supported at minimum intervals, which are specified by your local plumbing codes. A variety of metal and plastic materials are available for supporting plumbing pipes.
Step 8
Installing New Plumbing
Use plastic bushings to help hold plumbing pipes securely in holes bored through wall plates, studs, and joists. Bushings can help to cushion the pipes, preventing wear and reducing rattling.
Step 9
Installing New Plumbing
Always use manufacturer-recommended bushings with metal wall studs.
Step 10
Installing New Plumbing
Install extra T-fittings on new drain and vent lines so that you can pressure-test the system when the building inspector reviews your installation. A new DWV line should have these extra T-fittings near the points where the new branch drains and vent pipes reach the main waste-vent stack.
