How to Install Plumbing Vent Lines in Your Bathroom

Things You’ll Need


  • Old rag
  • Measuring tape
  • Pencil
  • Jigsaw
  • PVC primer
  • PVC cement
  • Toilet seal
  • Toilet bowl/tank
  • Nuts
  • Bolts
  • Caulk
  • Caulk gun
  • Wrench


  • Mounting hardware
  • Caulk
  • Drill
  • Nuts/bolts
  • Glue
  • Adapter
  • New sink fixture


  • Glue
  • Mounting hardware
  • New bathtub
  • Side panels/shower panels
  • Faucet
  • Level

How to plumb a bathroom sink

This bathroom lav is roughed-in with a 1.5” sanitary in the vertical position (please don’t use a wye here).

This makes our bathroom sink drain 1.5”, the vent 1.5”, the trap arm 1.5”, and the p-trap 1.5”.


How Toilet Plumbing Works

Before you start work, you need to understand a toilet . There are two main parts to a toilet, the tank and the bowl, and each has its own purpose.

Both of these elements work in tandem seamlessly so you can use your toilet every time. The diagram below gives some detail of the different components.

Cost of Moving Bathroom Plumbing

It is very common during a bathroom remodel to change the footprint of the room. Doing so opens new space or makes the layout work better for your family. If this is the case, you need to pay to have the various plumbing lines and drains moved and the installation of the various fixtures:

Fixture/MoveCost to MoveTotal Cost w/ Material and

Fixture/MoveCost to MoveTotal Cost w/ Material and Installation
Washing machine$160 – $400$170 – $500
Stack$200 – $400$250 – $450
Bathroom sink$240 – $600$540 – $6,100
Plumbing line in concrete$500 – $1,000$550 – $1,500
Toilet$200 – $400$550 – $3,900
Shower plumbing$240 – $600$1,740 – $4,100

Relocating Washing Machine Plumbing Cost

If your washing machine is in the bathroom and you want to relocate it, you need to have a new line run to where it eventually goes. This is $160 to $400, with parts making it $170 to $500. Most plumbers do not install or handle the actual washing machine, so these costs are just for the plumbing.

Cost to Move a Plumbing Stack

Your stack line is how your plumbing system vents. Most low-flow toilets use this line to vent air ahead of the flush, creating a vacuum to pull the waste through without much water. Moving the stack costs between $200 and $400 for each stack and costs more if you have a very steep roof. With parts, this project comes to $250 to $450 on average.

Cost to Move Bathroom Sink Plumbing

If you are moving your bathroom sink or adding a second sink to an existing wall, you need to have a new line installed. The cost to add a line is between $80 and $200 on average, and each sink needs three lines. The total cost of installing the new sink in its new location is $540 – $6,100, depending on the sink and style.

Cost to Move Plumbing in a Concrete Slab

This project is expensive because the concrete needs to be broken up to reach the plumbing before it can be located. So in addition to the cost of running the new line, you have added labor costs for however long it takes to reach the plumbing. This project’s total cost with materials is between $550 and $1,500, depending on how thick the slab is, how buried the plumbing is, and the plumbing type.

Cost to Move a Toilet

When you relocate a toilet, you need a new water line and also a new waste line. This makes two separate lines, with two different sizes and installation types per toilet that you move. The cost to move a toilet ranges from $200 to $400 just for the moving, with a total installation range of a new toilet in a new location of $550 – $3,900.

Moving Shower Plumbing to Another Wall Cost

If you decide to change your shower’s layout or move your shower entirely, you need to move three lines – the hot and cold water and the drain. Moving one line is $80 to $200, so the total cost of moving and installing a new shower is between $1,740 – $4,100 on average.

Get free estimates from plumbers near you

When Should I Use a Y?

  • In the drain system, use a Y-fitting to connect horizontal pipes (Photo 3). Along with a 45-degree “street” fitting, you can use a Y-fitting to run vertical drainpipes into horizontal pipes as shown. A Y-fitting can also be used in vent systems.

Set By Step Guide How to Plumb a Bathroom

2 Turns off the water to the home

  • Earlier than doing any work in your plumbing, you will want to show off the toilet water strains. Find the water valves and switch them off.

3. Set up the water strains

  • You will want to run 5 water strains into an ordinary toilet: a cold and hot line for each the tub/bathe and the sink, and a chilly water line for the bathroom.
  • You may both run these strains via the wall or up from the ground, relying on the placement of your toilet.
  • Connect versatile strains from the cold and hot waters line to the sink and bathtub taps.
  • Utilizing sandpaper, clear the copper pipes to make them easy, after which solder the lines to the primary water line.

4. Join the drain strains

  • To your toilet, you will want a number of sizes of drain strains. The drain line for the bathroom must be both a Three inch (7.62 cm) or Four inch (10.16 cm) line. After you connect the pipe to the bathroom drain, the pipe ought to slope downwards towards the primary drain line. So How to Plumb a Bathroom

5. Set the bathroom in place

Bogs normally are available in 2 items: a tank and a bowl. Begin by putting in the bowl.

  • Join the closet flange from the waste pipe to your rest room. To take action, glue the closet flange into place in order that the slots line up with the bathroom’s bolt holes.
  • It’s possible you’ll need to sit on the bathroom and rock backwards and forwards a bit to get it on appropriately.
  • Verify if the bowl is degree, after which tighten the nuts and the washers of the closet bolts.
  • Connect the bathroom’s tank to the bowl utilizing nuts.
  • Join the water line after which caulk across the base of the bowl to safe the bathroom.

6. Set up the sink

Begin by positioning the stand to do a take a look at match.

  • Mark the place the ground bolt ought to go and drill a gap via the sink stand and fasten it to ground utilizing a nut and bolt. How to Plumb a Bathroom
  • Join the sink to the cold and hot water strains. Additionally join the handles, stopper and drain to the highest portion of the sink. Etricka

We show you how to plumb a shower drain like a professional plumber. Follow our simple step-by-step guide with pictures & diagrams.

A clogged shower drain is not only annoying but can lead to water damage, pipe damage, and major plumbing issues if not taken care of promptly.

If you have a clogged shower drain, it is imperative that you take care of it quickly. We put together this article to talk about DIY shower drain plumbing.

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Break Out a Section of Drain

  • Cut into the main line so you can install a Y-fitting.
    • Pro tip: Make sure no one runs water (or flushes!) while the line is open.

Tips for Revamping a Current Bathroom

Whether you want to improve the value of your home or improve the way you feel about your bathroom, you can also consider giving an existing bathroom a facelift. This is a more affordable option than adding a whole new bathroom and can still achieve some great results. Consider these tips to help you revamp a current bathroom:

  • An affordable way to give your bath, shower or sink a new look is to replace the faucets with ones that have modern appeal.
  • Painting is a tried-and-true means of giving any room a fresh new look. You may also want to consider an accent wall with a fun wallpaper, tile or wood planking you love.
  • No one wants a dimly lit bathroom, especially at the vanity where you likely spend time getting ready. You also don’t want to have outdated light fixtures. If you’re dissatisfied with your current light fixtures, replacing them with bright ones you love is a great move.
  • The mirror over your vanity may need an update if it’s a plain, builder-grade mirror. Instead of replacing the whole mirror, consider adding a frame to give the mirror a more stylish look.


  • Consult a contractor and plumber if you don’t have experience with these types of projects.

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  • Measure everything and then measure again to double-check your measurements.

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Step 3

Now run a 3-inch diameter pipe (PVC) to the location of the toilet drainage. Make a turn of 90 degrees upward such that it will reach a level below the floor. Next, connect each pipe with two female adapters.

Use cement that is specially made for use with PVC pipes when making the connections. Use another elbow (90 degrees) to make the pipe turn horizontal again. Split the pipe with a pipe splitter to get two pipes.

Fixture Drainage

The sinks, shower and bathtub must also all connect to the existing drain and waste vent system, which means they must connect to the sewer and to the main vent stack. In practice, the events from all the fixtures often meet in a common pipe that connects to the main stack at a point higher than the highest plumbing fixture in the house. The drains may join, but it’s just as common for each one to have its own connection to the soil stack. Both drain and vent pipes must maintain a minimum slope of 1/4 inch per foot. A vent slopes toward the drain it services, and a drain slopes toward the sewer.

2. Cut Openings

After you plan out the basics, measure and mark the cutouts in your floor. Be sure to keep your measurements accurate and your marks clear. The next step is to cut and drill where you marked. Only then can you get ready to do the plumbing.

Common questions about adding a bathroom

Is there existing water and waste piping near your new bathroom?

Before installing, check to make sure that water flow exists for your new bathroom. If it doesn’t, you may need to hire a professional plumber to sort out your needs and get water flow to the room of your choice.

Do you have enough space for a bathroom?

An important question to consider, as not every space can fit all the bathroom necessities you may require. The starting point for most bathrooms is roughly 25 square feet-this size gives you just enough room for a small bathtub, a toilet and a sink, though keep in mind this size may be too small for you.

Does your city code allow you to add a bathroom in your designated space?

Another tricky subject as every city will be different and it is important for you to consult your nearest authority on the matter. Many cities do not permit alterations to your home or some extensions may be too large for city code without the right permits, so it is best to understand what you can and cannot do to your house before you begin.

Should you have a professional assist with adding a bathroom?

The short answer is yes. In many cases, electrical and plumbing alterations must be handled by a trained professional. If you are confident of your abilities and have the requisite experience, then some steps can be DIY, but ultimately, utilities must be handled by a professional.

Adding a bathroom to your home can help to increase the value of your home, but it would be best to consult a professional to assess your situation to prevent any unnecessary building mishaps that may occur and further costs as well.  

What You’ll Need

Equipment / Tools

1 Power saw 1 Level 1 Basic carpentry tools 1 Pipe strap 1 Fitting to join to existing drainpipe

Materials 1 PVC pipe and fittings to meet codes 1 PVC primer and cement

7. Install Your Sink

Determine where your floor bolt goes, and then make a hole in the sink base where the bolt will be. After that, attach the sink base to the floor with a nut and bolt. Connect the water lines to the sink, remembering to attach both the hot and cold lines. Attach the handles, stopper, and drain to the sink. Then, place the sink on the base. Using adhesive, attach the adapter and threads to your drain. 

Does adding a bathroom add value to your home?

Adding a bathroom will always increase the value of your home, but how much will largely depend on your location. The average return on the west coast of the United States is around 67 percent. East coast is roughly 47 percent, but this number will change largely on the materials and size of the bathroom you are adding to your home.

The Cost to Add Another Bathroom

Many people don’t even consider adding a bathroom because they are sure bathroom remodeling is too expensive. Finding the space and building it out, along with adding plumbing, makes the cost to add a bathroom seem prohibitively expensive. It doesn’t have to be. The key is to find the right approach so the benefit of an extra bathroom outweighs the cost. Remember, adding a bathroom can significantly increase your home’s value, so with the right approach to bathroom remodeling, the ROI can be strongly in your favor.

How much does it actually cost to add a bathroom to your house? Not considering the cost you’ll recoup, the upfront investment can run anywhere from $3,000 if you already have a space in your home to install the bathroom to $25,000 if you have to add on to the footprint of your home.

You can easily spend more than this if you’re looking to install a large, luxurious bathroom, or you can save if you work with your existing layout and opt for simple fixtures, so make sure you get a quote that takes your project specifications into account.

Does adding a bathroom to a house increase taxes? The answer depends on a few factors. If your project requires a permit, then a tax assessor may notice the additional value you’re adding to your home. If you add on to the square footage of your house, you can definitely expect an increase in taxes. Even if you end up paying a little bit more in taxes, the added value to your home will far outweigh this small expense.

The Toilet Drain

In the context of drainage, it is prudent to use long pattern fittings to ensure waste properly segues from vertical piping to horizontal piping. A closet flange is linked to a closet bend, typically with a 4-inch fitting along the inlet and a 3-inch fitting along the outlet. The closet bend outlet connects to the sanitary tee through a diminutive piece of PVC. The toilet drains downstream through the aforementioned vertical piping that connects to the horizontal piping.

PEX vs Copper Pipes

When you have a new plumbing line installed, your plumber usually uses either copper or PEX pipes. Copper is expensive and increases your installation costs, depending on how much you need. PEX is a flexible, plastic pipe, which is much less expensive. PEX costs remain stable while copper fluctuates.

While labor remains the same, you can save by asking your plumber to use PEX. Many plumbers have already made the switch and use PEX for most projects unless otherwise specified. Always ask what your plumber is using and if they can use PEX to help save on costs.

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Final Thoughts

While installing a basement bathroom is a worthwhile project that can augment a basement living area, it usually demands plumbing knowledge and expertise that the average homeowner typically doesn’t possess. While that doesn’t mean the DIYer should recruit a contractor to complete the entire job, it is a good idea to hire a professional to handle the plumbing upgrades such a renovation usually requires.

Plumbing the Bathroom

There are many different ways to vent your fixtures, and you’re going to want to cater to the factors present in your bathroom. The most common configuration is to feed 2″ PVC down from the ceiling within the wall behind the toilet. The vent pipe connects into the toilet drain pipe. The sink drain pipe and the tub/shower drain pipe are vented with 1.5″  pipe that branches off from the 2″ PVC mainline.

To complete this project you’re going to need PVC pipe, as well as DWV fittings and pipe. So let’s get on with it. Here is a sample configuration:

Example 1 (Pictured Above)

Example 1 (Pictured Above)

Through the floor, the toilet connects to the flange. The toilet flange connects to a 4″ x 3″ DWV closet bend, which then connects to a 3″ combo (which looks more like a sanitary tee in the image, that’s a little artistic error) which is also bringing in the air from the roof. The combo connects to a short run of DWV pipe which connects to a 3″ x 3″ x 3″ wye.

To the right we see the sink connects with a trap adapter to the sanitary tee, which is bringing in air from the main vent line. A small run of DWV connects the tee to a wye combo with a cleanout cap sealing the open end.

To the left we see the tub drain connecting with a P-trap to the sanitary tee, which is also bringing in air from the main vent line. Then with a tiny run of DWV, the tee connects to the wye combo.

The discharge end of the wye connects to the building drain.

How do I plumb a full bathroom?

“What about a bathtub? Or a shower?”“How do I plumb bathrooms with different fixture layouts?”

If that’s you, I’ve got good news.

We just put together an ebook that makes plumbing any bathroom dramatically easier. It’s called The Bathroom Blueprint.

It’s our new digital e-book that contains plumbing diagrams for 17 different bathrooms!

These diagrams will VISUALLY show you how a bathroom DWV system fits together.

We also are throwing in access to our private membership website.

Inside the member area, you get private access to plumbing tutorial videos never released to the public before.