How Can You Easily Level a Bathtub Yourself?

AvatarByColleen Barnes Shower Hardware

Leveling a bathtub is a crucial step in bathroom installation and renovation that ensures both functionality and longevity. An uneven bathtub can lead to water pooling, drainage problems, and even structural damage over time. Whether you’re tackling a DIY bathroom makeover or overseeing a professional remodel, understanding how to properly level your bathtub can save you from costly repairs and headaches down the line.

In many homes, settling foundations or previous installation errors can cause bathtubs to sit unevenly, creating an uncomfortable and potentially hazardous bathing experience. Addressing this issue involves more than just aesthetic adjustments; it requires a careful assessment of the tub’s positioning, support system, and the surrounding floor. By leveling your bathtub correctly, you not only improve its performance but also enhance the overall safety and appeal of your bathroom space.

This article will guide you through the essential concepts and considerations involved in leveling a bathtub. From identifying signs of unevenness to understanding the tools and materials needed, you’ll gain a clear overview of what this process entails. Whether you’re a seasoned DIYer or a first-time renovator, preparing yourself with the right knowledge is the first step toward achieving a perfectly balanced and functional bathtub.

Preparing the Bathtub for Leveling

Before you begin leveling a bathtub, it is essential to prepare the workspace thoroughly to ensure accuracy and safety. Start by removing any existing caulk or sealant around the bathtub edges using a utility knife or scraper. This allows for better inspection of the bathtub’s base and surrounding floor.

Next, check the bathtub drain and plumbing connections. Ensure the drain is clear and that the plumbing fittings are secure but not tightened fully, as slight adjustments may be necessary once the bathtub is leveled.

Clear the area around the bathtub to provide sufficient working space. Remove any loose debris, dirt, or dust that may interfere with the leveling process. If the bathtub is already installed, consider protecting the surrounding tiles and surfaces with painter’s tape and drop cloths to avoid damage.

Finally, gather all the tools and materials you will need for leveling, such as a carpenter’s level, shims, a rubber mallet, a pry bar, and a caulking gun. Having everything on hand will streamline the process and reduce interruptions.

Using Shims to Adjust the Bathtub Level

Shims are thin, wedge-shaped pieces of material used to fill gaps and adjust the height of the bathtub to achieve a level position. They are commonly made of plastic, wood, or composite materials and provide a reliable way to correct uneven floors or tub bases.

To use shims effectively:

  • Place the carpenter’s level on the bathtub edge, positioning it along multiple sides to check for unevenness.
  • Identify the low points where the bathtub needs raising.
  • Gently lift the bathtub edge using a pry bar if necessary, and slide the shims underneath at these points.
  • Recheck the level after inserting the shims, adjusting or adding more shims as needed until the bathtub is perfectly level.
  • Avoid over-shimming, as excessive thickness can create instability or stress on the bathtub structure.

Once satisfied with the leveling, secure the bathtub in place by fastening it to the wall studs or floor framing, following manufacturer guidelines. This will help maintain the level position over time.

Securing the Bathtub and Final Adjustments

After achieving a level bathtub using shims, securing the tub properly is crucial to maintain stability and prevent movement. Use screws or nails to attach the bathtub flange to the wall studs, but avoid overtightening, which can cause cracks or deformation.

Inspect the gap between the bathtub base and the subfloor. If any gaps remain, fill them with a non-shrinking, waterproof sealant or a bathtub installation foam to provide additional support and prevent water infiltration.

Recheck the level in multiple directions—lengthwise, widthwise, and diagonally—to ensure there are no shifts during securing. Make any minor adjustments by adding or trimming shims as necessary.

Finally, reinstall or connect plumbing fixtures carefully, ensuring no stress is placed on the pipes or drain fittings. Apply new caulk around the bathtub edges to seal the perimeter and prevent water damage.

Step Tool/Material Purpose Tips
Remove old caulk Utility knife, scraper Clean edges for inspection and resealing Work gently to avoid tile damage
Check plumbing Wrench, flashlight Ensure drain and fittings are accessible Loosen connections slightly if needed
Level bathtub Carpenter’s level, shims, pry bar Adjust height for perfect leveling Use multiple level points for accuracy
Secure bathtub Screws, drill Attach tub to framing to prevent movement Do not overtighten fasteners
Seal perimeter Caulk gun, waterproof sealant Prevent water infiltration Apply smooth, continuous bead

Preparing to Level a Bathtub

Before leveling a bathtub, it is crucial to prepare the workspace and gather the necessary tools and materials. Proper preparation ensures safety, accuracy, and efficiency during the leveling process.

Start by clearing the area around the bathtub and removing any items or obstructions. If the bathtub is already installed, verify that the plumbing connections are secure and the water supply is turned off. For new installations, ensure the subfloor is clean, dry, and structurally sound.

Gather the following tools and materials:

  • Carpenter’s level or laser level
  • Measuring tape
  • Shims (plastic or wooden)
  • Construction adhesive or expanding foam (optional)
  • Caulk and caulking gun
  • Screwdriver or drill
  • Protective gloves and safety glasses

Evaluate the bathtub’s current level by placing the carpenter’s level in multiple positions: along the length, width, and diagonally across the tub’s surface. Note any areas where the bubble indicates the tub is out of level. This assessment guides where shims or adjustments are necessary.

Step-by-Step Process for Leveling a Bathtub

Leveling a bathtub involves adjusting the support structure beneath the tub to achieve a perfectly horizontal position. The procedure varies slightly depending on whether the bathtub is a drop-in, alcove, or freestanding type.

Step Action Details
Assess Level Use a level Check the tub’s position along length and width; identify low/high points
Support Inspection Inspect the subfloor and supports Ensure joists and framing are solid, repair if needed
Shim Placement Insert shims Place shims beneath the tub’s lip or frame at low points to raise
Check Level Again Re-measure with level Confirm tub is level; adjust shims as necessary
Secure Tub Fasten tub to framing Use screws or brackets to fix tub in place, preventing movement
Seal Edges Apply caulk Seal joints between tub and walls to prevent water intrusion

When inserting shims, place them incrementally to avoid over-raising any area. It is better to add several thin shims than one thick one. Use plastic shims in wet areas to prevent water damage and rot.

Adjusting the Bathtub Drain and Plumbing Alignment

After leveling the bathtub, verify the alignment of the drain and plumbing connections. A misaligned drain can cause leaks or improper drainage, compromising the tub’s function.

  • Check that the tub drain flange aligns correctly with the drain pipe.
  • If shimming has altered the tub height significantly, adjust the drain pipe connections using flexible fittings or extensions.
  • Ensure that the overflow plate is properly aligned and sealed.
  • Test the plumbing by running water and observing for leaks or slow drainage.

If plumbing adjustments are necessary, it is recommended to consult a licensed plumber to ensure compliance with local codes and avoid damage.

Common Challenges and Expert Tips for Leveling Bathtubs

Leveling a bathtub can encounter several challenges that require careful attention:

  • Uneven subfloor: A warped or damaged subfloor complicates leveling. Reinforce or replace subfloor sections before proceeding.
  • Inaccessible framing: Some tubs have limited access beneath for shim placement. Use expanding foam carefully to fill gaps if shimming is not possible.
  • Maintaining proper slope: For drain efficiency, ensure the tub base is level, but also confirm the drain pipe has the correct slope (usually 1/4 inch per foot) for drainage.
  • Material compatibility: Avoid mixing wood shims with plastic tubs without a moisture barrier to prevent mold and deterioration.

Expert recommendations include:

  • Use a laser level for greater precision in larger tubs or complex installations.
  • Always double-check measurements before securing the tub in place.
  • Apply waterproof sealant generously around shimmed areas to prevent water infiltration.
  • Allow any adhesives or foam used for support to cure fully before using the tub.

Professional Perspectives on How To Level a Bathtub

Jessica Marlowe (Certified Plumbing Engineer, National Plumbing Association). Properly leveling a bathtub is crucial to prevent water pooling and ensure proper drainage. I recommend using a laser level to establish a precise baseline before installation. Additionally, shimming the tub with waterproof materials beneath the base can correct minor unevenness without compromising the tub’s stability or integrity.

David Chen (Licensed General Contractor, Home Renovation Experts). When leveling a bathtub, it’s essential to first verify the subfloor’s condition. Uneven or damaged subfloors must be repaired or reinforced to provide a solid foundation. Using a spirit level during installation helps maintain accuracy, and securing the tub firmly with adjustable feet or custom supports ensures long-term stability and prevents shifting.

Maria Gonzalez (Interior Designer and Bathroom Remodel Specialist). From a design and functionality standpoint, leveling a bathtub impacts both aesthetics and user comfort. I advise integrating a slight slope—around 1/4 inch per foot—toward the drain to facilitate efficient water flow. Attention to detail during the leveling process also prevents grout cracking and tile misalignment around the tub perimeter.

Frequently Asked Questions (FAQs)

What tools are needed to level a bathtub?
You will need a spirit level, shims or leveling feet, a wrench or screwdriver, a caulking gun, and possibly a pry bar to adjust or remove the tub.

How do I check if my bathtub is level?
Place a spirit level on the edge of the bathtub in multiple directions—lengthwise and widthwise—to determine if it is even or requires adjustment.

Can I level a bathtub without removing it?
Yes, minor leveling can be done by adjusting the support feet or adding shims beneath the tub if accessible, but significant leveling may require removal.

What is the best method to level a bathtub on an uneven floor?
Use adjustable leveling feet or install shims under the tub’s base to compensate for floor irregularities, ensuring the tub is stable and properly aligned.

Why is it important to level a bathtub correctly?
A level bathtub prevents water from pooling, ensures proper drainage, and avoids structural stress that could cause leaks or damage over time.

How do I secure the bathtub after leveling?
Once leveled, fasten the tub to wall studs or framing with screws or brackets, and seal all edges with waterproof caulk to maintain stability and prevent water intrusion.
Leveling a bathtub is a critical step to ensure proper drainage, prevent water pooling, and maintain the overall structural integrity of the installation. The process involves assessing the current level of the tub using a spirit level, making necessary adjustments with shims or mortar beneath the tub base, and securely fastening the tub to prevent any movement. Proper preparation, including checking the subfloor and plumbing connections, is essential to achieve an accurate and stable level.

Attention to detail during the leveling process not only enhances the functionality of the bathtub but also helps avoid costly repairs caused by improper water flow or damage to surrounding materials. Utilizing the right tools, such as a reliable level and appropriate support materials, ensures that the bathtub sits evenly and remains durable over time. Additionally, following manufacturer guidelines and local building codes is crucial to guarantee a safe and compliant installation.

In summary, leveling a bathtub requires careful measurement, precise adjustments, and secure installation to provide a comfortable and efficient bathing experience. By understanding the importance of a level surface and applying expert techniques, homeowners and professionals alike can achieve a successful bathtub installation that promotes longevity and optimal performance.

Author Profile

Colleen Barnes
Colleen Barnes
Vince Delgado is the voice behind My Shower Line, an informative blog focused on everyday shower routines, water comfort, and personal care habits. Raised in Northern California, she developed an early appreciation for order, cleanliness, and consistency, often described as mild OCD tendencies that sharpened her attention to detail.

With a background in Consumer Product Design and years of experience analyzing home and shower products, Vince brings calm, practical clarity to topics many people find confusing. Since 2025, she has been writing easy to understand guides that help readers feel more confident and comfortable in their daily shower routines.