Shower Pan Cracks (What’s Causing Them and How to Fix Them)

Having a shower pan crack unexpectedly can be an intimidating and frustrating home repair. It is not one that you think of needing to fix when you get a house, but luckily there are some DIY solutions to fix the damage. However, you will need to have a good understanding of your shower pan to do so.

Some of the most common reasons your shower pan has cracked are general wear and tear or poor installation. When the acrylic or fiberglass shower pans crack, you will probably see unexplained water on your bathroom floor. Depending on the material, you can fix a crack in the shower pan with epoxy or a polyester filler.

A small crack on your shower pan is certainly something you can fix on your own. Getting a good understanding of what a cracked shower pan looks like can help you fix it before the crack grows. Continue through this article to learn what the signs of a cracked shower pan are, how to prevent them, and how to fix them!

What is a shower pan?

Shower pans are a simple way to water seal the base of your shower. They tend to be made out of acrylic or fiberglass material. This is done because installers do not need to place individual tiles with mortar. Instead, they can set the bed of mortar, connect it to the drain pipe, and place it in one go!

They are a lot easier to clean than tile floors, so it is more than likely that your home has one of these shower pans. The problem with this is that the material can crack for a couple of reasons. Which allows water to seep into the crack and create the perfect home for mold and mildew. 

Shower Pan

How can I tell if my shower pan is cracked?

There are several signs that will tell you if the shower pan is cracked, besides seeing a largely visible break in the material! The first sign is if the pan bends or bows when you step on top of it. You will be able to hear the material bend or pop slightly when this happens. 

It usually occurs when the pan is not set properly, but you should look around the seals of the pan for any kind of damage. The danger with this type of break is that water can seep into the seal and further corrode it. Which will lead to a much more expensive repair bill. 

Another common sign of a broken shower pan is unexplained water on the bathroom floor. If there is always water on the floor after you use the shower and it certainly does not come from you, it is most likely a broken shower pan.

The next most common sign is mold or mildew in your shower. If you have a large crack you will likely see their green presence if you peer into the hole. Another example would be lots of green or black spots popping up on the wall area around the shower pan. You could also see these spots just around the pans’ seal.

Moldy spots usually mean your shower pan has been leaking for some time. Regular cleaning of your shower will keep the mold away, but it certainly will not fix the leak. You should also look out for mold spots on the ceiling below your shower if it is on an upper floor. This will also give a good indication if the pan is leaking.

Accompanied by the mold and mildew is a musty scent. If you smell must after walking into your bathroom or shower, it is a clear sign that there is a leak. The musty smell is similar to walking into an old basement. It comes from water getting trapped somewhere and not being able to evaporate or dry. 

What causes cracks in the shower pan? 

There are a handful of reasons your shower pan has cracked. Most of them happen gradually over time, so it is important to keep an eye out for them to prevent long-term damage. Keeping your shower clean and well-managed is a great way to prevent some of these causes.

One of the first and most common reasons for these cracks is simply regular wear and tear on the shower pan. Over time your house may shift, the sealant of the pan could break, and water can leak out. There is not much to do to prevent this from happening, but if you know you have an old shower, just keep an eye out for the signs we mentioned earlier!

Another problem that could cause your shower pan to crack is it experiencing too much weight. Extra weight can place too much pressure on weak parts of the pan and cause it to crack. This usually happens when combined with other factors like age or poor installation. 

Too much weight can cause a crack on your shower pan

Next is poor installation! Premade shower pans can come installed on a bed of mortar or on mortar-less pans designed to sit on a flat floor. Usually, if the shower pan is not set in mortar it is much more likely to have cracks in the future. 

But if either of these installations is done poorly, it sets up your shower to crack very easily later on. This is why you really should not attempt to install a new shower pan yourself. Even if it seems cheaper in the present, it could cost you a lot very quickly down the road.

In line with the effects of poor installation, thin or poorly supported shower pans can easily lead to cracking. If a shower pan has been shimmed on one side in an attempt to level it, the ribs may be unevenly supported. Which will make it more susceptible to too much weight or shift in the stability of the shower. Additionally, wooden shims will easily rot and collapse if exposed to water over time

Improper cleaning can lead to the general decay of your shower pan over time, leaving it more susceptible to cracks. You should be very careful about using cleaning chemicals that deteriorate the materials of your shower pan. 

Anything that could erode acrylic, ABS, polystyrene, fiberglass, or plastic materials should not be used. Solvents such as turpentine, mineral spirits, paint thinner, and acetone can crack the surface of the pan. So keep an eye out for them when buying shower cleaners!

Usually, shower pan cracks come from a combination of several of these causes. Avoiding them the best you can is a great way to prevent future cracks from occurring. However, some simply come with the shower and just need patching up every once in a while!

How do I fix my shower pan?

You likely have one of two types of shower pans in your home, which are fiberglass or acrylic. They are the most common shower pans, and the most common to break. Fixing these different types requires different tools and steps, so here is a breakdown of each process!

Fixing a fiberglass shower pan 

For this type of shower pan, you will only need some epoxy, a piece of sandpaper, and maybe some scrap plywood if you have a large hole. It is possible to fix larger cracks with scrap plywood and epoxy since the base is mostly flat, but small cracks will only need epoxy and sandpaper.

Material needed to fix a shower pan

First, you will need to clean the crack or hole of any debris. Then spread epoxy on the plywood (or simply the crack) and firmly press it in. If you are working with a large hole, do this step from the unexposed side of the pan to seal it. With a small crack, just let the epoxy dry then sand it down to smooth. For the large hole, you need to apply an upper layer of epoxy on the exposed surface and then sand it down.

Fixing an acrylic shower pan 

Dealing with an acrylic shower pan is a bit more complicated than fiberglass, but it can still be repaired rather than replaced completely! This project requires a drill, sandpaper, insulating foam, a two-part polyester filler, a rubber spreader, a bathtub repair paint, and a urethane compound.

The first step will be to clean the area of any debris or mold. Then you will drill 1/4-inch holes in a 1-foot square around the damage. Be careful to avoid drilling all the way through. This sets you up to stabilize the acrylic after you’ve fixed the crack.

Next, you will fill the hole with insulating foam. Then clear away any foam leaking from the hole or crack with a knife before sanding the area over. Let this sit for a while to ensure it has been set properly.

Then you must drill holes on either end of the crack without going all the way through the acrylic. Next, with a two-part polyester filler, you will spread the product evenly over the holes and crack them with a rubber spreader. Let this filler dry out.

Now you need to smooth out the repaired surface with the sandpaper again. Once it is smooth, wipe the area with denatured alcohol to remove dust. Finally, you will apply a bathtub repair paint, let it dry, then add a final layer of urethane compound. Buff this spot one more time to create a smooth, hard finish. And you are done!

How much does it cost to fix a shower pan?

Fixing a shower pan in your costs a lot less than hiring a professional. Once you have established the types of materials you need, and in what amount, the cost can range from $100 to $500. This is mostly because you will likely need to buy tools and products that are not lying around your house. But you certainly could do it for much cheaper depending on what you are working with

If you hire a professional to fix or even replace your shower pan, it can cost between $500 and $2,000. For those with minor damage and an easily identifiable crack, fixing it on your own is easily doable and more cost-effective. However, if you have a major issue that’s been going on for a while, you will probably need to hire someone.

Replace Or Fix? 

Deciding on whether you should replace or fix your shower pan largely depends on the damage. If you have lots of molds all over the shower and lots of water on the floor when you use it, you probably need to replace the whole pan. It is expensive, costing roughly $2,000 to call a professional and buy a new pan.

However, if you only have a small crack that you recently notices you can easily fix it on your own! With a few tools and sealants, you can fix the small crack for approximately $200. As long as the crack is a reasonable size and you do not see extensive damage, you can certainly handle it on your own.


For those who live in an old house with an old shower, you will probably need to repair the shower pan at some point. They can break down from general wear, too much weight, or poor cleaning over the years.

Luckily, if you have a small crack with no extensive damage there is a simple DIY solution for your problem. The materials for this project can sometimes be pricey, but end up being much cheaper than hiring a professional to do a task you are capable of!

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