How To Level A Bathtub Or Toilet On An Uneven Floor

In this detailed guide, I will show you how to level a bathtub or toilet on an uneven floor. As you’re aware, no one wants to be dealing with an unlevel floor.

Not only can it cause your bathtub or toilet to become unlevel, but it can lead to a litany of problems. The good news is that you can level the floor and alleviate all the problems that can come with it.

It is imperative to know how to level out your flooring because of the issues that can occur with your bathtub on unlevel flooring. So, how do you level a bathtub or toilet on an uneven flooring? Follow this guide.

Why It Is Important to Have a Level Bathtub Or Toilet

There are more than a few answers here. Long story short, it is important to have level flooring under your bathtub. There are a multitude of problems that can happen when your bathtub or toilet is unlevel.

First and foremost, water can accumulate in a corner or corners of the tub. If you notice that water tends to be higher in a corner or two, it is a clear indication that your bathtub is not sitting level.

Secondly, there is the chance that mold could form. Whenever water accumulates for a long period of time, it is the gateway to mold.

Even your tub, when facing longer periods of accumulation, can see mold form. The last thing you want to deal with is mold. Thirdly, you could have water leaking when your tub is not level.

Besides the aforementioned mold growth, there is a chance that water could accumulate and damage areas of the bathroom. Never underestimate the potential for water damage where leaks are involved.

Finally, an unlevel bathtub or toilet could lead to improper drainage. When the tub can’t drain properly, it leads to a disgusting scene.

Yes, there is the potential for mold, but that’s not it. When your tub or toilet can’t drain properly, there are different bacteria that can form and live in your tub. No one wants that.

How To Level A Bathtub Or Toilet On An Uneven Floor

Before you begin, you need the right tools for the job. You will need a level, a board, some metal or wood shims, a trowel, premix mortar, a measuring step, a utility or putty knife, and some silicone caulk.

Even if you don’t have them readily available, you can grab them at your local home improvement store for relatively inexpensive.

It is important to note that using the mortar method means that you will need a friend along to help. The good news is that it is not time-consuming to perform.

The Mortar Method

The first way to level your tub is through the mortar method. Mortar is similar to concrete in that it is a hardening mixture that is laid down as a foundation on which the tub rests. The process takes a day and a half – installation and drying.

Step 1: Measure

Grab your measuring tape and measure out the distance between the base of the tub and the side flanges. While you are at it, measure the length of each of the legs. The legs are typically hidden beneath the mortar.

If your tub does not have a decorative leg, you will need to measure the dimensions of the tub. When you are doing this, trace the outline of where you will need to install the tub later on in the process.

Step 2: Mixing the Mortar

With all of your measurements down, you can start to mix the thin-set mortar. For the most part, you just need the mortar and some water. Just make sure that you mix it thoroughly, giving the mortar a chance to thicken.

When the mortar mix is ready to go, use your trowel to spread it over the marked area. Keep spreading out the mortar; it has to be an inch or so deep to be effective. Make sure that you smooth it out as you go.

Step 3: Put the Tub on the Mortar

When you are comfortable with how your mortar is sitting, put the tub or toilet on top of it. This is where you will need a friend to get things done as most of us can’t lift a tub on our own.

When you are done putting the tub or toilet onto the mortar, make sure that you push it down. Keep pushing until the flange touches the floor. This allows the tub to set into the mortar and get a more secure base.

Step 4: Repeat

There are four sides to a bathtub, so you will have to do this for the other three. Make sure that you push down on each of those sides so that the tub sits level in the mortar.

When you have pushed all four sides in, make sure that it is leveled. Grab your measuring tape to verify the measurements and your level to ensure that everything is sitting as it should.

For the toilet, just push it down into the mortar and use a level to ensure the toilet is installed upright and not at an angle.

Step 5: Clean and Dry

There will no doubt be excess mortar sitting under the tub or toilet. Use your trowel to scrape off most of the residue. Just make sure you do it before the mortar dries or you will be in for a lot more effort to remove the mortar.

Clean the floor, the tub, and any other spots that may have gotten the mortar on it. Allow the mortar the proper time to dry – about 24 to 30 hours – and do not be impatient about it.

When the mortar has a chance to properly set, it becomes the strong foundation that you need to level out an unlevel bathtub.

The Shim Method

Don’t want to mess with mortar and the mess that it can create? There is another method. You can implement shims to raise the bathtub level, creating a level tub.

You can use metal shims, but don’t be afraid to use hardwood shims as well. The process is also relatively straightforward.

Step 1: Add in the Shims

This will also require a friend because you will need someone to lift the tub up so that you can add the shims underneath. Make sure that you put shims under the legs or the base of the tub.

The good news here is that you have options when it comes to the shims that you can use. Either use metal shims, wooden shims, softwood shims, or hardwood shims.

Just be aware of how those shims may compress due to the weight of the tub and the water over time. Factor that in if you can; ask a professional if you aren’t certain.

Step 2: Repeat

You will need to create an evenness throughout, so adding more shims will be required. Ideally, you would only need to do this at the four corners but if your tub does not have legs, it may take more than a few.

Ensure that you check the levelness as you go. Don’t just blindly add shims without checking to see your progress as you go.

Step 3: Testing the Level and Adding Caulk

It is imperative that you check the levelness of the tub with each shim that you add. Don’t just check in one spot, either. Measure at all four sides of the tub to ensure that it is sitting level. Adding a shim here or there may create an imbalance in the other direction.

When you are confident that it is level, lift the tub again and use silicone caulk to keep the shims secured in place. You don’t want to slide the shims under only for them to shift or move over time, hence the need for the caulk.

Do this all the way around, using caulk anywhere you have placed shims. Keep checking the levelness as you go. You have to work relatively quickly as caulk can sometimes dry fairly quickly.

Step 4: Clean and Dry

When you have finished adding caulk to all of the shims, make sure that you clean the floor and the tub. Caulk that is allowed to harden and dry can be much more difficult to remove than wet caulk.

Make sure that you get any residue up as well; it might not be super visible while wet but will definitely stand out when it dries. If the caulk does manage to dry before you wipe it off, you will have to scrape it.

Caulk typically needs about 24 hours to completely harden, so make sure that you do not use the tub over that period of time. Otherwise, you run the risk of the shims shifting or the caulk moving, potentially leading to that unevenness once more.

An Uneven Floor Is Fairly Common

While it’s great to know how to level an unlevel tub or toilet, you may be wondering “is it bad that my floor is not level?” While it certainly is not ideal, it also is not necessarily a cause for concern, either.

More often than not, an uneven floor is because of poor installation. A previous owner may have laid new tile or flooring over the old one, creating an imbalance that can be very subtle yet still noticeable.