Tricks of the Trade
How to install a new toilet flange
by Billy Stutz
Toilets are a necessity in any home, and proper installation is a must to ensure they work as intended. Plumbers, builders and trade professionals know that a key component to toilet installation is the fitting that connects the toilet to the drain pipe known as the closet flange or toilet flange. No matter what you call it, this small and often inexpensive plumbing part can cause significant damage if not installed correctly. Toilets that are set without a securely installed closet flange can wobble, crack and even leak.
As important as this part is, there are two primary methods for setting a toilet flange: above the floor and flush with the floor. Depending on the job, one method may be beneficial over the other. Learn about the two ways to set a toilet flange and the pros and cons of each method.
Setting a closet flange above the floor
The more popular option for closet flange installation is setting it above the floor, which means the underside of the flange is placed higher than the finished floor. When installing a closet flange above the floor, it’s recommended to install the flange a quarter inch above the finished floor. A wax ring is also required to securely mount a toilet and create a tight seal. By installing a flange a quarter inch above the floor, there is adequate room to allow for enough wax to properly seal the flange in place and keep water from escaping. The flange is further secured by closet bolts that anchor it to the floor.
The pro for setting a closet flange above the floor is that it provides added protection from future toilet leaks. The con is that there is a greater margin for error if the floors are not installed already. If the flange is placed too high, the toilet may become unstable and shaky. Fortunately, there are other parts you can install to prevent that, like toilet shims and closet bolts of different lengths.
Pro tip: Setting a closet flange above the floor may be the better option if you’re installing a toilet in a bathroom with finished flooring.
Setting a closet flange flush with the floor
The other option for installing a toilet flange is to set it flush with the floor. The process for setting it this way is similar to the above-the-floor method in almost every way including the requirement for a wax ring and closet bolts. The essential difference with this method is simply that the closet flange is set to the same height as the finished floor.
Setting a closet flange flush with the floor also means that the wax ring is further down from the toilet itself, which may make it more difficult to create a leak-free seal. The benefit is that setting a closet flange flush with the floor eliminates the possibility for a shaking toilet resulting from a flange that was mounted too high. Another benefit of setting the flange flush with the floor is that it involves less interaction with cutting or working around the flooring.
Pro tip: Setting a closet flange flush with the floor can be the right method if you’re installing a toilet in a bathroom with unfished floors.
Though installing a closet flange above the finished floor may be the preferred method, it’s not the only method. The key takeaway is to understand the advantages and disadvantages of each method in order to know which route to take depending on the bathroom. Whether you call it a closet flange or a toilet flange, Ferguson has the right part of the job. We make it easy to buy plumbing supplies online and in store at our plumbing counters.