How To Fix A Cracked Bathtub

A crack in your bathtub can cause major problems, including leaks that could damage the floor underneath. But if you do have a crack in your bathtub, replacing the whole tub can be quite expensive. Did you know that fixing a cracked bathtub yourself can be done for a lot cheaper? We’ve done the research to teach you how to do this.

The method that you use will depend on the type of bathtub you have. Fiberglass and acrylic tubs will require a little more work because you have to clean, sand, and fill in the crack. Cracks in porcelain tubs are an easier fix; all you need is a little caulk. Unfortunately, cracks in metal tubs will need to be fixed by a professional.

It is actually not that difficult to fix a cracked bathtub. Depending on the type of tub you have, it can be done in as little as a day or two. In this article, we’ll cover everything you need to know about fixing a crack in a tub, whether it is made of fiberglass, acrylic, or porcelain. Continue reading to learn more.

A faucet turned on inside the bathroom, How To Fix A Cracked Bathtub

What Causes A Bathtub To Become Cracked?

It always seems like bathtubs are made from pretty sturdy materials, and it’s true that most of them are. But even the sturdiest materials can become accidentally damaged or cracked under certain circumstances.

If you see a crack in your bathtub, it can be confusing because you may not know how it got there. And even though you can fix the crack, it could be just a temporary fix if a larger problem caused the crack.

Up close photo of a cracked bathroom bathtub

That means that even if you do fix the crack, it could return over time if you don’t get to the root of the problem. If the tub continues to crack after repairing, the tub itself may not be the problem. You may have to do additional repair work eventually.

Here are the three main causes of cracks in your bathtub:


One of the most likely causes of cracks in your bathtub is due to heavy objects being dropped repeatedly. Dropping shampoo bottles or having the shower curtain rod fall into the tub could both cause cracking over time. This is more common in porcelain and acrylic tubs.

When heavy objects are dropped, they may not form a crack right away. But they can cause dents, which can weaken the material that the tub is made of. If the material becomes weak enough, it could eventually crack. This type of crack is known as a stress crack because it was caused by too much stress being put on an object.

Materials And Installation

Sometimes cracks can form simply because of the material that was used. Materials like fiberglass are more flexible than other materials. Fiberglass can crack easily due to too much pressure, especially if the tub wasn’t installed properly or there isn’t enough support underneath the tub.


Lastly, heavy cleaners such as bleach can also cause cracks in your bathtub. Bleach and abrasive cleaners can take off the finish on certain bathtub materials. The finish is there to protect the bathtub from moisture and aid in durability. If the finish is taken off, it leaves the bathtub vulnerable and makes it easier for it to crack.

A white ceramic bathtub inside a narrow bathroom

Can You Fix A Crack In A Fiberglass Tub?

Cracking is most commonly seen in fiberglass tubs. Fiberglass is a type of plastic that is more flexible than other materials and is also more porous. That means that moisture and stress can both cause cracks in fiberglass tubs.

Because cracks in fiberglass tubs are so common, bathtub repair kits have been developed specifically for fixing cracks in fiberglass tubs. These kits should contain almost everything that you need and can be purchased at most home improvement stores. 

Can Acrylic Tubs Be Repaired?

Like fiberglass, acrylic is a type of plastic, but it isn’t as flexible as fiberglass. However, acrylic tubs can still become cracked. But since they are made of plastic, the kits you can buy to repair cracks in fiberglass tubs can also be used to repair cracks in acrylic tubs.

Note that you can purchase bathtub repair kits in different colors to match the finish of your bathtub.

Click here to see this fiberglass and acrylic bathtub repair kit on Amazon.

How To Fix A Crack In Fiberglass/Acrylic Bathtub

If you’re unsure what your tub is made of, you can gently tap it with a hard object. If it sounds hollow, it is either fiberglass or acrylic. 

You will first need to gather your materials:

  • Bathroom cleaner
  • Sponge
  • Fine-grit sandpaper
  • Microfiber cloth
  • Gloves
  • Bathtub repair kit

Clean The Area

Use the bathroom cleaner and the sponge to clean the area around the crack. This will help ensure that the repair products adhere properly to the bathtub.

Sand The Area

Next, use the fine-grit sandpaper to sand the area around the crack. This will create an even surface. Sometimes, the bathtub repair kit will come with sandpaper. After you have sanded the area, use a microfiber cloth to wipe off the dust.

Mix Up The Filler

Most bathtub repair kits come with a filler that you have to mix up. Read the instructions for how to do this. Be sure to wear gloves to protect your skin and mix it in a well-ventilated room. The filler usually consists of a resin and a hardener that must be mixed together properly in order to be effective.

You should also check to see whether or not your kit has a color that you add to the filler. Some kits do, while others come with paint that you use after the filler has hardened. Add the color to the filler according to the instructions, then test a small area to make sure that the color matches.

Apply The Filler

Next, use the applicator to apply the filler to the crack and the surrounding area. Press down on the filler so that it actually goes inside the crack. Spread out the filler around the crack until the surface is smooth and consistent.

Allow The Filler To Dry

Give the filler plenty of time to dry. Usually, it will have to dry overnight, but the instructions for the repair kit should tell you how long the drying time is. After it is dry, use the sandpaper again to sand over the repair to create an even surface.

After sanding, use the microfiber cloth again to remove dust. Use paint to hide the repair if your kit came with it. Allow the paint to dry completely before using the tub.

How To Fix A Crack In A Porcelain Tub

If your tub is made from porcelain, then the method of repair can be a little different. Some bathtub repair kits do work on porcelain as well. If you find a kit that does, you can follow the same steps above for repairing fiberglass and acrylic tubs.

But, you can also fix a crack in a porcelain tub with a little bathroom caulk and some paint. You will need:

  • Bathroom cleaner
  • Sponge
  • Bathroom caulk
  • Porcelain paint
  • Paintbrush

Clean The Area

Use the sponge and bathroom cleaner to clean the area around the crack. Be sure to dry the area before proceeding.

Apply The Caulk

Squeeze the caulk into the crack until it is completely filled. Use caulk that has a nozzle for more control. Then, wet a paper towel and use it to wipe off the excess caulk. Allow the caulk to dry completely.

Paint Over The Caulk

Match porcelain paint to the color of your bathtub. Then, apply the paint over the repaired area with a paintbrush. Allow the paint to dry completely before using the bathtub.

Click here to see this porcelain paint on Amazon.

See more: How To Prepare A Bathtub For Painting

How Much Does It Cost To Fix A Cracked Tub?

Fixing a cracked tub is a lot cheaper than replacing the whole tub. For fiberglass and acrylic tubs, all you will need to buy is a bathtub repair kit, which costs around $20 to $25. It costs around that much to buy caulk and paint for porcelain tubs as well.

Is A Fiberglass Or Acrylic Tub Better?

In general, acrylic tubs are better than fiberglass because they are more durable. Acrylic tubs are also more expensive, but they are less likely to crack over time. Fiberglass is a flexible material, so it is more likely to become cracked or damaged over time.

See more: Porcelain Vs. Acrylic Tubs- Which To Choose?

Does Tub Reglazing Last?

Remember that sometimes bathtubs can crack when the finish wears off. Reglazing the tub can help prevent cracks from happening. If you do the reglazing yourself, it can last 3to 5 years as long as you care for it properly.

But if you have it done professionally, it can last up to 15 years. This is because professional reglazing uses more durable materials.

Final Thoughts

Repairing a cracked tub is possible with just a bit of know-how and the right materials. Now, you can extend the life of your tub. Remember, you can color match too so your tub will be as good as new. 

One comment

  1. It is also great that you provided the types of bathtub to consider when you fixing a cracked bathtub. It is important for us to know what will be the process needed to achieve and repair our bathtub. Thank you for sharing this article.

Leave a Reply

Your email address will not be published. Required fields are marked *