How To Tell If Your Shower Pan Is Leaking (Find Out Now!)

Upgraded Home Team
by Upgraded Home Team

Shower pans are an important component of your home’s bathroom. They collect water from the shower drain before moving it down the drain. With continuous use, shower pans are subject to wear and tear and hence leaks. When the shower pan starts to leak, a timely replacement is necessary to prevent water damage to your home.

If you notice an increase in mold and mildew on or near your bathroom floors and the presence of cracks on the shower pan, chances are that it’s leaking. The formation of pools of water at the base of your shower and leaks on your home’s foundation could also mean that your shower pan is leaking.

Shower pans are typically made from ceramic, cement, or tough plastic. Nevertheless, a lot could go wrong if a shower pan is subjected to continuous or even incorrect use. Hence, it’s best to identify common shower pan problems, including water leaks, and how to correct them.

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What Causes Shower Pans to Leak?

Many things can cause a shower pan to leak, including:

Wear and Tear

Although shower pans are built to last for years, their function makes them vulnerable to wear and tear. For starters, the constant traffic and flow of water, soap, shampoo, and cleaning agents takes a toll on the pans’ surface. A properly installed shower pan will serve you for years, but not forever.


When your shower pan wears out, cracks will undoubtedly appear. Often, this is the first sign that a shower pan has reached the end of its life cycle. Cracking of often caused by an underlying issue, including shower pan movement. When you notice a crack, it’s essential to find out the possible cause so that immediate action is taken.

With a concrete shower pan, hairline cracks are common in the grout joints. When you notice them, it doesn’t mean that your shower pan has become useless. Conversely, cracks affect the waterproof capabilities of plastic shower pans and their ability to absorb movement. Thus, even the smallest of cracks could be a sign of trouble.


A shower pan should be solidly mounted to prevent movement during use. However, if it’s not tightly fixed using the required sealants, bolts, and calk, it will start moving when in use and eventually crack. When cracks form, water will seep into the underlying floor and your home’s foundation via the crevices.

If there’s a movement of any kind, that’s a sign of installation failure. Whether they are made of concrete, ceramic, or plastic, shower pans are built in a manner that prevents unnecessary movement. Even the slightest movement will result in broken seals and cracks around the plumbing.

If you opt for a plastic shower pan, it’s best to screw it firmly into the wall studs during installation. Also, ensure it is sturdily locked in by the wall installation. With plastic shower pans, you can either install them directly above the subfloor or on a layer of thin-set mortar, which bonds them onto the substrate. Either way, there shouldn’t be any movement.

Deflection of any kind affects your pan’s waterproof capability. If either the pan itself or the floor beneath shifts for whatever reason, cracks and leaks will follow. Hence, it’s important to mount shower pans on rock-solid surfaces. This will prevent movement once you start using it.

Poor Drainage

A shower pan’s main function is to direct water from the showerhead and channel it into your home’s drainage system. To do so, it needs to be set at a specific gradient. Failure to set the shower pan at the recommended gradient means water will take longer to drain from the shower. Hence, there’s the risk of the water accumulating in the area between the shower pan and the drain.

Tell-Tale Signs of a Shower Pan Leak

A shower pan leak can cause significant damage to your property, especially if it goes unnoticed for a long time. Since shower pans differ, the damage that results from leaks also differs. A leaking plastic shower pan will damage your property differently from a concrete one.

A leak can destroy tiling, rugs, wood, and sheetrock. The water damage can also cause molding, which is often difficult to control. Here are the tell-tale signs of a shower pan leak:


If water starts to leak through a shower pan’s surface, it’s common for stains to appear on the drywall. You’re also likely to notice stains, walls, and even on the ceiling in the room beneath the bathroom. Cracking or bubbling paint, and a bulky and saggy appearance on the sheetrock, especially if it’s overhead, also point to a shower pan leak.

Mold and Mildew Formation

This is the first thing to look out for if you suspect there’s a shower pan leak. If the leaking shower pan is located on the first floor of your home, the water will need to escape somewhere. Often, this is usually the bathroom floor or the outer brick ledge.

It’s difficult to detect the flow of water if there’s a leak in your shower pan. You’ll only realize it after a significant amount of damage has happened. In this regard, check out for green or black discoloration around the brick ledge or slab to catch the problem early.

Water Pools

Sometimes, shower pan leaks can be quite substantial. If you notice water pouring out from nearby crevices after turning on the faucet, chances are that the shower pan is leaking. If that’s the case, avoid using the shower until a plumber inspects it thoroughly. The appearance of water pools is often caused by problems with the drain, pan, or even the fixtures.

Checking Your Shower Pan for Leaks

If you notice any of the signs above, it’s best to undertake a simple test to determine that whatever is happening in your bathroom is actually a shower pan leak. Remember, the water pools, stains, and mold can be caused by water from somewhere else rather than a leak in the shower pan. So, here’s how to inspect your shower pan for leaks:

Seal the Shower Drain

An easy way to check for leaks is by sealing the shower drain. This can be done using either a rubber plug or duct tape. Ensure that the seal is water-tight, or otherwise, it will be difficult to determine the source of the leak.

Flood the Shower Pan

After sealing the shower drain, pour a specific amount of water into the shower pan. This could be a bucket or two. Afterward, use a marker pen to note the water level.

Observe Changes in the Water Level

After eight hours or so, observe whether there’s a change in the water level. If the water level goes down, it indicates a leak in your shower pan.

Fixing a Leaking Shower Pan

If you establish that your shower pan has a leak, there are several ways to fix it. The method you choose depends on the cause of the leak. You should also remember that when fixing a leaking shower pan, you may need to modify your home’s floor or foundation. If the repair job is significant, it’s best to leave it to a plumber. That said, here are some solutions for a leaking shower pan:

Use a Masonry or Epoxy Sealant

Epoxy is a quick fix for a leaking shower pan, but it prevents further leaks until you figure out a long-term solution. You can apply this sealant on loose areas or cracks to prevent water from seeping out. A masonry sealant can also be used in the same way as to prevent leaks.

Opt for Pre-Fabricated Pans

If there’s significant leakage, your shower pan won’t hold up for too long, however much you fix the issue. Large cracks will still leak even if you seal them. Therefore, if your cement or plastic shower pan is significantly damaged, consider replacing it with a prefabricated unit.

Unlike traditional shower pans, the prefabricated ones require some expertise when installing. Hence, you may need to hire a plumber to do the job. Once installed, you’ll enjoy years of leak-free and uninterrupted use.

Pan Liner Replacement

Sometimes, leaks result from cracks in the contact area between your shower pan and the surrounding area. If that’s your predicament, fix the cracks using a pan liner. Likewise, if the current pan liner has deteriorated, have it replaced. This will ensure that water stays within the pan and only moves to the drain.

Grout Replacement

With continued use, the grout will wear out, thus necessitating a replacement. If you notice that your shower pan is leaking due to grout deterioration, you should apply new grout immediately. The new grout should be accompanied by a sealant recommended for your type of shower pan.

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Final Thoughts

A leaking shower pan can cause costly damage to your property. Whether your bathroom already has a shower pan, or if you intend to add one during remodeling, it’s essential to know the tell-tale signs of leaks and ways to mitigate water damage if there’s a leak. It’s equally important to have an idea about the common causes of shower pan leaks. This will enable you to implement measures to prevent them.

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Upgraded Home Team
Upgraded Home Team

We are a team of passionate homeowners, home improvement pros, and DIY enthusiasts who enjoy sharing home improvement, housekeeping, decorating, and more with other homeowners! Whether you're looking for a step-by-step guide on fixing an appliance or the cost of installing a fence, we've here to help.

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