Does a Toilet Flange Need to Be Screwed or Bolted?

I was getting ready to replace my toilet and noticed that some of the YouTube videos I consulted didn’t use screws or bolts to hold down the toilet flange. I have a concrete floor and am not looking forward to drilling new holes, so I found it intriguing to see some use a type of epoxy instead of screws and bolts. But is it safe to not use screws or bolts?

Does a toilet flange need to be screwed or bolted to the floor? Yes, you have to screw or bolt the toilet flange to the floor. If you do not, you risk not securing the toilet enough to prevent rocking that may damage the wax seal, the drainage pipe, or the floor. A bad seal between the toilet and the flange or the flange and the pipe can cause leakage, which will damage the bolts that hold the flange to the pipe or allow horrible smells to seep into your bathroom.

So, what is the proper way to install a new toilet flange? I’ll share with you all I learned. Here is how to do it.

Supplies You’ll Need to Secure Your Toilet Flange

To get your toilet flange installed properly, you are going to need the right supplies. Here is a list of the things you should gather, either from your tool shed or your local hardware store.

Toilet Flange: There are all different styles, and materials flanges are made out of. Make sure you are using one that is proper for your situation, not just the cheapest one at the store. Ask a specialist at the store if you have any doubts.
Wax Ring: This connects the flange to the toilet, so no water leaks out.
Drill (or hammer drill): You are going to need a drill of some sort. If you are installing into a cement floor, it is best to get a hammer drill. You should have no problem renting one if you don’t have one of your own and aren’t looking to buy one.
Drill Bits: Obviously if you are drilling you are going to need bits, but if you are installing into concrete or a tile floor, you are going to need carbide or diamond-tipped bits
Cooling Oil: If you are drilling into concrete or tile, this will help prevent your drill from overheating.
Hardware: To install into a normal sub-floor, you just need normal screws or bolts, but once again, if you are installing into concrete you are going to need special hardware> There are a few choices you can go with. Tapcon screws are a very popular choice but lead anchors can be easier to install.
Putty Knife: You will need this to scrape away lingering wax from the previous seal.
PVC Primer and Glue: You need to adhere the drainpipe and the flange.
Toilet Flange Spacer: You will only need this if your flange sits under the finished floor. It is important that the flange is high enough for the wax seal to work properly. A spacer will allow you to bolt the flange to the sub-floor and still set the wax ring where it needs to be.
Silicone Caulk: This is only used with the toilet flange spacer. You will need it to seal the spacer to the flange.

Bolting In The Flange

Once you have the toilet separated from the old flange, installing the new one is rather easy. It is basically just a matter of cleaning out the old parts and properly fastening the new ones. To install your new toilet flange once you have your toilet removed:

Clear the old wax from the base with your putty knife.
Take off the old flange. This may require some prying and snapping of the flange as it should have been glued to the drainpipe.
Once the area is clean, brush primer and glue on the surfaces of both the flange and the pipe.
Drop the flange into the pipe until the flange sits on either the sub-floor or the finished surface.
If the flange is resting on the sub-floor, now is the time to put on the spacer. Cover the undersurface of the spacer with silicone caulk and place the spacer over the flange, lining up any screw holes.
If you are installing into a wood floor, screw the flange and/or flange spacer into the floor.
If you are installing into concrete and there are no holes already there for you to secure the flange with, use your hammer drill and carbide or diamond-tipped bit to drill the needed holes to secure the flange to the floor. Be careful not to angle towards the pipe; any damage to the pipe will cost you time and significant money.
If you are installing into a tile floor, use a normal drill setting with a carbide or diamond-tipped bit that has been dipped in cooking oil. Twist the drill back and forth a few times to prevent slipping. Start drilling on the lowest speed setting your drill has until the bit bites into the subfloor, then speed up until you reach the desired depth.
Once all of your holes have been drilled, change out your bit for a screwdriver attachment or use a screwdriver to drive Tapcon screws, or whatever type of fastener you are using, into the floor.
Once the toilet flange has been secured to the floor, put on bolts to attach the toilet to the flange, place the wax ring in the proper position, and put the toilet back in place.

Important Things To Consider

Properly installing your flange is an important task. Any short cuts or mistakes that you make can lead to damage to the floor, the drainpipe, or the toilet. Here are some other important considerations you make before or while installing your toilet flange.

Use all pre-drilled holes: the flange manufacturer pre-drilled a certain number of holes to secure the flange to the floor. That is the number of screws or bolts that they felt are needed to give the toilet bolts the support they need. Use all of the holes when securing the flange to the floor.
Don’t be cheap: there are plenty of low-cost plastic flanges, but many plumbers will tell you that the plastic flanges tend to break. Also, flanges with cheap metal tend to rust. Try to find a quality flange with a stainless steel ring, and you most likely won’t have to replace it for years to come.
No higher than ⅛”: Remember, never set your flange under the level of the finished floor. There are products on the market that can help you raise the height of the flange. Also, you need to make sure that it doesn’t stick out any more than ⅛” above the finished floor. If the flange is either too low or too high. The was seal will not compress right, and your toilet will leak, causing damage to your floor and releasing swage smells.

So, don’t try adhering your toilet to the floor with adhesive or epoxy. Your toilet is not something to take short cuts on with the installation. You need to use screws or bolts to secure the flange to the floor, or you risk damage to the toilet, the drainpipe, or your floor, leading to more costly repairs. Follow these easy steps, and you should have no issues