Fixing Toilet Drainage Problems

By Tim Carter
©1993-2010 Tim Carter

Summary: A toilet that leaks often centers on the toilet flange. If your toilet moves, you can repair the toilet flange and stop toilet leaks.

DEAR TIM: My toilet leaks at the floor level. I am convinced it has something to do with the fact that it rocks side to side each time it is used. Upon removing the toilet I noticed the metal ring is rusted and the toilet bolts have nothing to grab onto. I would prefer not to cut into the drain lines if possible. What is the best way to fix this? Steve W., Lawton, OK

DEAR STEVE: Toilets are not supposed to act like rocking horses, that's for sure! It is vital that toilets are securely attached to the drainage system and that there is a seal in place between the toilet and the drain system. The seal prevents sewer gas from invading your home and it insures that all toilet waste goes down the drain and not into your home. Toilet seal problems are significant health hazards and require immediate attention.

Plumbing drainage systems have special fittings that make the transition from the pipes to fixtures. Beneath sinks plumbers use a fitting called a "desanko". This fitting has a nut and a washer on it that allows you to connect the P trap pipe to the drainage system. As you tighten the nut, the washer compresses around the P trap pipe and creates a waterproof and airtight seal. Unfortunately we can't do the same thing with toilets.

Toilets are connected to the drainage system using a toilet flange. The flange fitting should be set so that the top of the flange is about one quarter inch above the finished floor surface. The flange contains several holes that allow you to securely fasten it to the wood or concrete floor beneath the flange. It is very important that the rim of the flange is supported by the floor. The weight of the toilet and anyone using it should never be transferred to the drainage pipes.

This flange fitting has special slots in it that toilet bolts fit into. The toilet bolts extend vertically through the flange and pass through the holes in the base of your toilet bowl. Using nuts and special washers you then tighten the bowl to this flange.

You can purchase a flange extender ring that simply fits over your rusted metal flange. These extenders usually come with a special paste gasket seal. You must use this sealant or silicone caulk between the new flange extender and the old rusted ring. This joint absolutely must be water and gas proof. Visit a traditional plumbing supply house to obtain this flange extender.

Once your new flange is in place, you must make the connection between the toilet and the flange water and gas proof. This is accomplished by installing a wax ring on top of the flange. Wax rings come with or without a horn. A horn is a plastic diverter that directs water into the drain pipe. I prefer wax rings that have this horn. The wax is very sticky and works very well as long as the toilet does not move once the bowl is in place. This is where many rookie plumbers and homeowners make a critical mistake. They move the toilet to some degree after it is in position.

Click here to watch a toilet flange installation tip video.

Toilet bowls should be installed so that they are level side to side and front to back. The trouble is most bathroom floors are not level. Once your flange extender is in place I want you to set the toilet on top of the flange without the wax ring in place. Use wood shims and a two foot long level to get the toilet so that it is indeed level. Gently lift the toilet off the flange without disturbing the wood shims.

Place the wax ring onto the flange with the horn pointing down into the drain pipe. Be sure the toilet bolts are sticking up through the special slots in the flange. The wax ring often will hold these bolts in place. Slowly and carefully position the toilet onto the wax ring. A helper is handy at this stage and will make sure the bolts make it through the holes in the base of the bowl. Lower the toilet slowly until it contacts the wood shims. Tighten the toilet bolts and grout the space between the floor and the base of the toilet. When the grout sets carefully remove the wood shims and fill these holes with the same grout. You will enjoy years of leak free performance!

Comments:

TJ Thayer
26 Dec 2008, 10:30

I bought my home about 6 months ago. Last night water started leaking at the bottom of the stool. I pulled the stool and found that the previous owners did not raise the line when they intalled tile. There is about an inch of room. Is there a piece of PVC I can add or do I double up on wax rings.

Thanks,

TJ

Jrice
20 Jan 2009, 10:50

Toilet has vacuum problem. Venting issues?

Mark Clauss
25 May 2009, 10:32

My daughter owns a fairley new condo ( 3 years old ) in Chicago. She is on the 6th floor. Her neighbor below has water dripping onto her bathroom ceiling. The maintaince man claims the water is coming from my daughters toilet. He stated the leak is from a seal in her toilet. She has no signs of water any where in her bathroom, nothing on the floor and the toilet level is not going down. The maintaince man wants my daughter to pay for the repairs and damages done to the neighbors ceiling. This sounds like it is a problem between floors not her toilet. What do you think?
Thank you,
Mark

Dan
01 Jul 2009, 20:55

on flush, toilet seems to be ok, but the water does not drain from the bowl. It takes time for the water level to go back down to normal. Tried plunging, but no help.

Larry
11 Jul 2009, 12:12

I have a toilet that will not retain water in it after flushing it. The water drains out very slowly util there is none.

Malcolm
29 Jul 2009, 14:41

Hi, my toilet is leaking from the toilet end that connects to the drainage waste pipe. It still has the ring or whatever it is called attached to the ceramic part of the toilet but is away from the plastic part of the pipe. I have tried readjusting it but still leaks. Do I need to change the ring thing or can the leak be fixed with the existing one? I don't what the ring thing is called.
Please help.
Best wishes
Malcolm

Peter
03 Aug 2009, 20:15

Hi, the toilet flange in my upstairs bathroom is cracked. I want to replace it but the flange is glued to the abs piping. How can I safely remove it without causing any damage to the drain pipe?

megabucks
04 Dec 2009, 10:11

How do I stabilize a toilet where the floor is not level?

John
23 Feb 2010, 15:15

i was fixing a toilet for my mother where the toilet didn't seem to touch the wax ring at all i am concerned that this could leak will a flange extended work to fix this issue ?