How to Install a Toilet

Co-authored by Dave Jones

Last Updated: December 14, 2021 References

Installing a new toilet is a lot easier than you may think. In fact, many homeowners choose to remove their old toilet and replace it with a new one without the help of a handyman or plumber. If you do decide to making installing a toilet your new DIY project, you should know the basics. This article will teach you how to remove your old toilet and replace it with a brand-new one to give your bathroom a breath of fresh air.

Method 1

Method 1 of 2:
Removing the Old Toilet

1
Measure the distance from the wall to the floor bolts before removing. Standard toilets have a measurement of 12" from the wall to the floor bolts. If your toilet measures 12", you can expect to buy any standard toilet and install it comfortably in the existing location without much hassle.^{[1]
X
Research source}
2
Turn off the water off at the supply valve. This is so that no new water rushes into the toilet basin while you're busy trying to remove it.^{[2]
X
Expert Source

Dave Jones
Master Plumber, Roto-Rooter Plumbing & Water Cleanup
Expert Interview. 13 December 2021.}^{[3]
X
Research source}
3
Flush the toilet to empty the basin and bowl.^{[4]
X
Expert Source

Dave Jones
Master Plumber, Roto-Rooter Plumbing & Water Cleanup
Expert Interview. 13 December 2021.}^{[5]
X
Research source}
4
Put on heavy duty, protective, rubber gloves to guard against any harmful bacteria that call the toilet or its surroundings home.^{[6]
X
Expert Source

Dave Jones
Master Plumber, Roto-Rooter Plumbing & Water Cleanup
Expert Interview. 13 December 2021.}^{[7]
X
Research source}
5
Remove any leftover water in the toilet bowl and toilet basin. You can use a small cup at first, and then switch over to a heavy-duty sponge. Dump the excess water into a bucket and dispose of it somewhere safe.
6
Unscrew the tank bolts that fasten the basin to the bowl.
7
Unscrew the water supply line.
8
Using your legs instead of your back, remove the basin by lifting it from the bowl. Place it somewhere convenient where it can't transmit unwanted bacteria.^{[8]
X
Expert Source

Dave Jones
Master Plumber, Roto-Rooter Plumbing & Water Cleanup
Expert Interview. 13 December 2021.}
9
Remove the floor bolt caps and unscrew the nuts with an adjustable wrench.^{[9]
X
Expert Source

Dave Jones
Master Plumber, Roto-Rooter Plumbing & Water Cleanup
Expert Interview. 13 December 2021.}
10
Break the sealant on pedestal of the toilet by rocking the it back and forth. You don't need to go overboard; a little bit of rocking goes a long way. After the seal has been broken, move the bowl away from the bathroom, preferably alongside the basin.
11
Scrape away remaining wax around the drain opening. You're going to be creating a new seal, so you want as much of the old sealant to be removed for proper sealing.^{[10]
X
Expert Source

Dave Jones
Master Plumber, Roto-Rooter Plumbing & Water Cleanup
Expert Interview. 13 December 2021.}
12
Plug the drain opening with an old rag or another implement. This will keep the sewage fumes from wafting into your bathroom before you install the new toilet.

Method 2

Method 2 of 2:
Installing the New Toilet

1
Replace the old flange around the drain opening with a new one. Unbolt the old flange and place the new flange over the hole. Next, drive in any mounting bolts through the flange and into the floor.^{[11]
X
Research source}
- You only need to replace the old flange if it is bent or broken. Otherwise, just leave it in place.^{[12]
  X
  Expert Source
  
  Dave Jones
  Master Plumber, Roto-Rooter Plumbing & Water Cleanup
  Expert Interview. 13 December 2021.}
2
Fit a new wax ring around the bottom of the toilet bowl, just around its drainage hole. Wax rings come either plain or with a funneled inside edge.^{[13]
X
Research source}
3
Ensure flange is tight to floor. If the flange is not tight on the floor it may be necessary to remove the wax ring and try again. Tighten or replace the flange screws if necessary.^{[14]
X
Expert Source

Dave Jones
Master Plumber, Roto-Rooter Plumbing & Water Cleanup
Expert Interview. 13 December 2021.}
4
Lift and place the toilet bowl over the anchor bolts protruding from the floor. This step is tricky and may take several tries, and you may need someone to help you.^{[15]
X
Expert Source

Dave Jones
Master Plumber, Roto-Rooter Plumbing & Water Cleanup
Expert Interview. 13 December 2021.}
5
Once the anchor bolts fit snugly inside the floor bolt openings, rock the bowl from side to side in order to create a seal on the toilet drainage hole. Shimmy the toilet form side to side much like you did to remove the old toilet (see above).
6
Insert the bolts through the tank and base, then tighten lightly by hand. Be sure not to over-tighten these bolts too much or tank will crack.
7
Insert shims or other spacers underneath the toilet to make it level.
8
Tighten the floor bolts gradually with an adjustable wrench until secure. Tighten one side a bit, and then move on to the other side. In other words, tighten simultaneously as much as possible.
- Over-tightening can result in a cracked bowl. Get the right balance between sealed and too-tight.
9
Install the decorative caps over the floor bolts.
10
Carefully fit the basin over the bowl, making sure the basin bolts fit inside the bowl. Tighten the basin bolts by hand. Do not over-tighten.
- If the bolts are too long to cover with the decorative caps, cut the excess length with a hacksaw. Just make sure to leave at least ¹⁄₂ in (1.3 cm) above the nut so the covers can fit over them securely.^{[16]
  X
  Expert Source
  
  Dave Jones
  Master Plumber, Roto-Rooter Plumbing & Water Cleanup
  Expert Interview. 13 December 2021.}
11
Reconnect the water line and turn on the water supply. Don't over-tighten the connection.^{[17]
X
Expert Source

Dave Jones
Master Plumber, Roto-Rooter Plumbing & Water Cleanup
Expert Interview. 13 December 2021.}^{[18]
X
Research source}
12
Caulk around the base of the toilet to ensure a good seal.

Community Q&A

Question

Is it necessary to caulk around the base of the toilet?

Community Answer

If you caulk around the base, you will not know if it is leaking. It's a nice touch, but not good to do. If the toilet sits level and looks good to the floor, then don't caulk it. I have installed many toilets. If it does not leak, let it go.
Question

How do I change bolts?

Community Answer

You can buy the bolts from a hardware store. If you're just replacing the bolts and keeping the bowl, you will have to take the bowl out to get to the bolt.
Question

My second-floor toilet leaks to the first floor every time it is flushed. What is the problem?

Community Answer

Check if the toilet rocks or moves. If it does, that points to a bad seal of the wax ring. Otherwise, one of the drain pipes may not have been glued, allowing water to leak.
Question

Why is my new toilet leaking around the bottom?

Community Answer

The new wax ring is probably leaking; you may need to renew it. You can tighten the bolts around the bottom just a little bit, and then several days later give just a little additional tightening. Don't crack it.
Question

After I removed the old toilet, I found some lead bent over the old flange. Should it be removed, and how?

Kyle Boutski

Community Answer

Never remove the lead, as this is part of the drain. This should be carefully bent over the flange after installation. This may be done using a hammer as you lightly tap the lead a little at a time. Careful, it's very soft and easy to split.
Question

One of the bolts broke off at the bottom of the bowl. Should I get a new bolt?

Community Answer

You will have to remove the toilet to replace the broken bolt. Toilet bolts come in a kit of two in a pack. You will have to get a toilet wax ring also.
Question

What do I do if I installed a new toilet and I have a bad smell coming from my bathroom?

Community Answer

The wax seal has cracked or broke. All you need to do is remove and reinstall the toilet with a new wax seal.
Question

Should the top of the flange be above top of floor or level with top of floor?

Community Answer

The bottom of the flange should be level with the finished floor, basically the flange sits on the floor and protrudes that 1/4". If the top of the flange is level or lower than the floor you may be able to get away with jumbo seal or stack two seals.
Question

What happens if the distance is 10" from the wall instead of 12" when installing a toilet?

Community Answer

When purchasing a replacement toilet, it is important to first check the "rough-in" size. Existing bolts that are 10 " from the wall indicate a 10 inch rough-in size.