How to Install a Toilet? Step-by-Step Advice

Not plumber, but I've installed a number of toilets. My advice is to ditch the wax ring and use a Danco Perfect Seal. Wax rings can work OK, but they can also be problematic if you're not experienced using them. One common problem with wax rings is if the floor isn't flat, the toilet will rock slightly in use, leading to evenual failure of the wax seal. Also, if you mis-align the toilet the first install attempt and then try to re-seat it on the wax ring, you can deform the wax in a way that causes it to leak.

The Danco design prevents leakage even if the toilet rocks, and is more forgiving of re-positioning the toilet during install. It also allows for a wide range of flange heights above or below floor level.

You must read and follow the instructions for the Danco, as there are two removable pieces (a black hard plastic ring and a blue soft silicone ring) that you may or may not need to use, depending on how the floor flange is set (ie how high/low the flange surface extends above/below floor level). So after you remove the old toilet and scrape the old wax ring off the flange, be sure to check the flange height above/below floor surface, and read and follow the Danco instructions for that particular flange height.

https://www.homedepot.com/p/DANCO-Perfect-Seal-Toilet-Wax-Ring-with-Bolts-10826X/206393853

Also buy a pack of plastic toilet shims and use them during install to shim any gaps and prevent the toilet from rocking if the floor isn't flat.

One common mistake is over-tightening the bolts that hold the toilet to the flange. Over-tightening can crack the toilet base, or it can crack the flange if the flange is PVC. Just make the bolts snug, after shimming if necessary to prevent rocking. It's a flat floor or shims that stops the toilet from rocking, not the bolts. And if you can't make the toilet sit flat on the floor, that means your flange is sticking up too high and preventing the toilet from sitting flush on the floor. In that case you may have failed to remove the extender pieces from the Danco ring.

The first thing is to choose the correct toilet.

Measure from the back wall to the bolts that fasten the toilet to the flange. Most often that measurement will be twelve inches. That is what's called the "rough in measurement".Toilets are commonly offered in ten, twelve and fourteen inch rough in measurements. Yours most likely will be a twelve inch but take that measurement anyway.

The next is wether you want a round or elongated bowl, a comfort height or common height and a selected color. And do you want it in a one or two piece.

I would look for a toilet that offers a cylinder type flush valve and not a flapper. Cylinder type seem to be less problematic. Kohler has a few models that are very good in this design.

When you pull the old toilet up look to see if the floor underneath is rotted. Check the flange to make sure that it is also not rotted out. If it is, there are replacement flange rings that work nicely when installed properly. It should be level or about a quarter inch above the floor and fastened with screws that are water resistant.

I use wax gaskets. Sometimes two. One deep with a "horn"against the flange the other a regular wax gasket on top of that one.

-one toilet

-one or two wax gaskets

-One flexible braided closet riser/supply tube at the required length. (longer is easier than shorter)

-One or two replacement closet flange ring and ring spacers .

-one set of jonni bolts.

-Screws for the flange.

There are also plastic and rubber shims that are available just in case you need them.

If you decide to purchase this at a big box hardware store like Lowes or HD get all the things mentioned on that list. You can return what you don't use.

Before you go to the store, turn the water off before you leave to make sure the water shuts off at the toilet. If not, add a shut off valve to your list.

Luv it! But this is a do it your self person @Mad Dog_2. I was trying to take it easy on him.

I remember long ago the plaster use. Never was made to do it in my 45+years. I also remember being taught to us a donut made of plumbers putty instead of a wax gasket. Never did that either. Gotta Luv your list just the same.

After the bowl and tank are dry, I would remove the tank and take it outside.

Then remove the bowl to take out. Easier than lugging the complete assembly.

Getting old…….

I always bring an old newspaper for the job. Use putty knife to remove wax and wipe it into the newspaper, then fold the paper up to contain the old wax.

Use part of the paper to make a softball size plug to put in the flange if not installing the new WC immediately. (sewer gas and debris protection).

And I know from experience that if you forget the paper plug, it will flush away….don't ask.

And also I put the bowl down first and then add the tank…..still older….though I always have added the tank after the bowl…even when younger.

It is a easier job just setting the bowl first.

In old houses there are often surprises after removing the bowl. I have even found carriage bolts thru the floor with nuts in the basement. Many times no flange, just lead riser peened over onto the floor and lag bolts into the wood or remains of such.

Mad Dog is a New York artist and that's a first class New York installation. I think Chicago is the only other town setting bowls in plaster?

And is New York the only place outlawing those exploding hoses and requiring a 3/8" copper supply pipe? Have you seen the toilet supply hose that caused $3.6 million in damages? The plumber's insurer paid every cent.

Hey Dog… how about the marble closet slab if the floor's wood?

Marble are nice & I recently posted a Picture of a really nice porcelain one. Mad Dog

Solid brass closet bolts are getting harder to find. All my local suppliers only have the thinly coated iron ones which are guaranteed to rot.

And I always double nut the bolts; first to the flange and then to the bowl.

Opinions on 1/4-20 vs 5/16-18 for closet bolts?

I used 5/16-18 my self, but it seemed like that wasn't common.

Clarify for me because I'm a little confused. Who is Andrew? Is he the forum moderator now?

is that a stud you thread in and out of the tee nut to adjust the length?

I stay with "Johnny Bolts" whatever brand? Hercules? Thick, solid brass. But those look cool. Andrew is fambly...Mad Dog

Intplm....Who makes those closet flange bolts? Mad Dog

Its not just you. Some replacement flanges are a bit flimsy. Some full flanges too. I also try to avoid the plastic flanges. I have been using the stainless steel ones. Stainless prevents a lot of hassles.