How To Shim A Toilet

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Uneven toilets are frustrating and can cause significant hygiene and health issues if left untreated. Pooling water in the bowl can lead to foul odors, bacteria growth, staining of your bathroom surfaces, and a long-term mess that could take hours to clean up.

It’s vital to immediately get your toilet shimmed for evenness to ensure a healthier living environment. Shimming not only helps with the appearance of your bathroom but also helps it to function efficiently.

We’ll walk you through how to shim a toilet, from selecting the correct shims and supplies to the necessary steps to complete the job. With the right tools and a little patience, you can level your toilet and create a healthier, more efficient bathroom environment.

What’s a Toilet Shim?

Tahikem Plastic Shims 8 Pack Table Wedge Clear Toilet Shim, Levelers Adjustable Blocks

A toilet shim is an efficient and cost-effective way to stabilize a lopsided or unsteady toilet. This essential tool utilizes either plastic or wooden wedges that can be inserted beneath the base of your throne, allowing you to adjust its height and tilt, so it remains level. Measuring between 7.5 – 9 inches long and 1.5 inches wide, they are the perfect size for getting into those hard-to-reach places.

Installing a toilet shim will assure you that your commode is secure and level whenever it’s used. Its leveled surface eliminates any rocking motions, ensuring every bathroom trip is safe for everyone in your home.

How to Shim a Toilet?

Shims’ installation will assure you that your toilet is safe and secure, allowing you to use it without any worries. With the right tools and a little know-how, you’ll be able to get the job done in no time. 

Materials Needed

Steps to follow

To shim a toilet, follow these three steps: 

1. Clean the base of the toilet

Before you begin shimming, be sure to thoroughly clean off any dirt and grime that may have accumulated near the base of the toilet. This will allow the shims to fit tightly, providing a better hold and more effective toilet leveling.

2. Search the gap

Inspect the area around the toilet base using a flashlight for any gaps. If you find one, measure its depth with a ruler to determine how many shims you will need.

3. Insert the Shims

Once you have measured the gap, insert the appropriate number of shims beneath the toilet base. Press them firmly so they are secure and won’t move when your toilet is used.

4. Tidy up the shims

Once the shims are in place, use a putty knife or rubber spatula to level out their edges gently. This will give your toilet a cleaner, more even appearance and ensure it is adequately secured. 

Different Types of Shims

Depending on the size and shape of your gap, you may need to use different types of shims. For example, some toilets require a thin, wedge-shaped shim, while others may need a thicker, flat one. You can purchase toilet shims at most hardware stores or online retailers.

Plastic toilet shims 

Plastic toilet shims are inexpensive and easy to install but can wear down over time. They are typically used for wide gaps or spaces that require a thicker shim.

Rubber toilet shims

If you’re looking for a shim that can provide the same level of stability and is incredibly durable, then rubber toilet shims are an ideal option. They’re more resistant to wear and tear than plastic or wooden ones and are much more straightforward to install and remove.

Frequently Asked Questions

Does the toilet need to be perfectly level?

Yes, it is essential to make sure that your toilet is level. This will ensure that the water flows correctly and provide a safe, comfortable experience whenever you use the toilet. A slight angle is acceptable, but a level toilet is the best option for the most part. 

Should shims be glued?

Depending on the material, shims can hold together more securely without slipping if there is friction. Some wood shims may even need to be glued; however, in most cases, this should not be necessary as the natural friction of the material will work well enough to keep them stable.

Do you screw through shims?

No, you should not screw through shims. This can compromise the stability of your toilet and may even cause it to wobble or rock. Instead, use shims to fill the gap between the floor and your toilet, then secure them in place with screws. 

Can you use cardboard as a shim?

Using cardboard as a shim is a big NO. The cardboard is not strong enough to provide the level of stability that you need for a secure installation. Instead, you should use metal or plastic shims for the best results. 


Shimming a toilet is an essential step in the toilet installation process. Using shims correctly lets you securely level your toilet and provide a safe, comfortable bathroom experience. Remember to measure the gap before purchasing the appropriate shim type, insert them firmly and level out their edges with a putty knife or rubber spatula. You can easily level your toilet quickly with the proper technique and materials.

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