How To Plumb A Bathroom: DIY Project Guide
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Bathroom Plumbing: A Step by Step Bathroom Guide

Have you recently purchased a “fixer-upper” and can’t wait to get started with DIY improvement projects? Or maybe your current bathroom just needs a facelift due to some outdated appliances. Either way, you’re probably scouring the internet trying to learn how to plumb a bathroom. There are definitely a lot of bathroom plumbing projects that should be left to the professionals (like if you’re gutting the entire room and adding new pipes), but there are a few DIY-friendly projects that any handy homeowner can tackle. Today we’ll be looking at three:
  • Installing a shower or tub faucet 🛁

  • Installing a new toilet 🚽

  • Installing a bathroom sink 🧼

Install a Shower or Tub Faucet 🚿

Installing a faucet in a shower or tub is a little tricky, but with enough time and patience, handy homeowners can handle this project. You’ll need to set aside about half of a day to complete this project. Materials Needed:
  • Pencil

  • Drill

  • Propane torch

  • Flame guard

  • Faucet

  • 2×6 braces

  • Screws

  • Copper pipe and fittings

  • Solder

  • Hammer arresters

  • Drop-ear elbows

  • Galvanized nipple fitting

  • Pipe-thread tape

Step 1: Determine the Faucet Placement

Once you’ve chosen the faucet you like best, you can begin the installation! First, determine the placement. You’ll want to position the faucet 28 inches above the floor for a tub and 48 inches above for a shower. You’ll need to determine where to place the braces behind the faucet. Keep in mind the total depth of the finished wall that will go over the faucet (usually 0.5-inch-thick backer board plus 0.25-inch-thick tiles.)

Step 2: Anchor the Braces

Once you’ve determined your positioning for the spout, faucet handles, and showerhead, you’ll install a 2×6 brace for each component. Anchor the braces into your wall’s paneling with screws.

person installing bathroom tub faucet

Step 3: Assemble the Pipes

Then, you’ll need to assemble your copper pipes to connect to the water supply. Install a 3/4-inch pipe up to the height of the faucet. Then, add reducer couplings or elbows and attach short 1/2-inch pipes to the threaded adapters on the faucet. Then, add hammer arresters and anchor the faucet according to the manufacturer’s instructions.

Step 4: Sweat the Fittings

Grab that propane torch because it’s time to sweat. Once all your pipe connections are solid, sweat the fittings to ensure they’re tightly bound. (Be sure to place your flame guard behind the pipes so you don’t burn your house down.) You’ll start at the faucet and then move to the shower arm and spout connections.

Step 5: Tighten and Install

Attach drop-ear elbows at both places where the pipes were sweated. Then, finger-tighten a galvanized nipple fitting into both drop-ear elbows. Once the wallcovering is fully installed, you’ll remove the galvanized nipple fitting and install the shower arm and tub spout in their place. And voilà! This project can get complex, especially if you aren’t comfortable sweating your own copper pipes. Don’t be afraid to pass this one off to the pros to ensure your personal safety and the structural safety of your bathroom.

Install a New Toilet 🚽

If you’re wanting to upgrade your porcelain throne, installing one yourself is easier than you may think. All you’ll need to do is remove the old toilet, add a new wax ring, and secure the new toilet in place. Be sure to have a buddy help you with this project so you don’t strain anything lifting the heavy toilets!

Step 1: Remove the Old Toilet

The first thing you must do when replacing a toilet is turn off the water supply. Locate your water shut-off valve on the wall or the floor near the toilet and turn the knob to shut off the supply. Flush the toilet to drain all the water, and use a sponge and bucket to remove any remaining water. Disconnect the supply line with an adjustable wrench, and wipe up any water that spills from the supply line with a rag. Use an adjustable wrench to remove the bolts that connect the bottom of the toilet tank to the bowl. Lift the tank straight up and set it aside. Then, take off the toilet bolt caps and use an adjustable wrench to remove the nuts and washers on the bolts that are securing the toilet bowl to the floor. If your toilet is caulked to the floor, use a utility knife to score through the caulk. Rock the toilet bowl back and forth gently to lift it free. Move it aside with the help of your buddy.

Step 2: Replace the Flange if Necessary

Next, remove the old toilet seal (wax ring) with a putty knife. Stuff a rag into the open sewer line in the floor to prevent sewer gas from escaping. (Remove the rag before installing the new toilet.) Now, inspect the toilet flange, which connects the toilet to the drainpipe in the floor. If it’s cracked or broken, replace it with a new flange.

Step 3: Install New Wax Ring

You’ll need to attach a new wax ring to seal the toilet to the floor. You can do this in one of two ways:
  • Lay the new toilet on its side and attach the new wax ring to the bottom of the bowl, or;

  • Place the seal in position on the flange before lowering the new bowl into place.

Step 4: Line Up and Bolt New Toilet

Place the new toilet onto the flange, aligning the bolts in the flange with the bolts in the bottom of the bowl. Press down to activate the seal. Don’t move or tilt the toilet after pressing it down, as it could cause future leaks. Then, bolt the bowl to the floor by placing a washer and nut on each bolt and tightening the nuts onto the bolts. You want the bolts to be secure but be careful not to over-tighten them.

plumber installing a new toilet

Step 5: Attach the Tank

If you have a one-piece toilet with the tank already attached, you can skip this step. But if you have a two-piece toilet, you’ll need to attach the tank to the bowl. Insert the tank bolts and washers from inside the tank. Place the tank onto the bowl, aligning the bolts with the holes in the bowl. Secure the tank to the bowl by fighting each bolt until the tank pulls down and is flush with the bowl. Reattach the water supply line to the exposed portion of the fill valve. (The valve will stick out of the bottom of the tank.)

Step 6: Install Toilet Seat + Lid

Last but not least, install the new toilet seat and lid. Position the seat over the bowl and attach it according to the manufacturer’s instructions. Then, you’ll turn the water supply back on and allow the tank to fill up. Flush the toilet and make sure there aren’t any leaks.

Install a Bathroom Sink 🧼

The last DIY-friendly bathroom plumbing project we’ll outline is installing a new bathroom sink. This is yet another project that’s easier when another person helps you out.

Step 1: Turn Off the Water and Remove the Old Sink

Just like with installing a new toilet, you’ll need to shut off the water supply to your sink before starting. There are likely two knobs below the sink— turn them both off and then turn your sink knobs to make sure no water comes out. Use a pipe wrench to disconnect the water supply and drain lines from the faucet. Also, look for the large metal or plastic nut that connects the sink to the drain and disconnect it. Then, loosen and detach the P-trap section of the pipe. Use a putty knife to loosen the caulk around the sink’s perimeter, lift it up, and move it to the side.

Step 2: Install the New Faucet

To install the new faucet, you’ll just follow the manufacturer’s instructions that came with the faucet. If you plan to reuse your old faucet, take note of how it was originally installed so you can duplicate the setup.

person installing a new sink

Step 3: Secure the New Sink

For a drop-in sink, place the unit in place and either secure it with the gasket it comes with or use a plumber’s putty or caulk to create a seal. If you’re installing an undermount sink, you’ll need another person to hold it in place. Apply the caulk or plumber’s putty to the top rim before pushing it up into place. Then, add any bolts as necessary.

Step 4: Reconnect the Water Lines and P-Trap

Wait 24 hours before moving on to this next step so that the caulk can dry. Then, reattach the P-trap and water lines by screwing the nuts back into place.

Step 5: Apply Caulk to the Sink and Drain

Apply a bead of caulk around the outside of the sink, and remove any excess that spills out. Wait another 24 hours to test the sink to make sure the seal is solid. Then, turn the water supply back on and run the water to ensure nothing leaks.

Intimidated? Call a Professional Plumber Instead

Even though these bathroom plumbing tasks are DIY-friendly, they can be confusing and intimidating to undertake. If you don’t feel confident about giving these projects a go, don’t worry! Simply leave it to a professional plumber like 4Front Energy to handle your projects with ease. At 4Front Energy, we’ll tackle all of these projects and more with confidence. Reach out today for a free consultation!

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