Shower Door Leaking at the Bottom? Here's How to Seal It Properly

Is your glass shower door leaking at the bottom every time you take a shower?  

Tired of plugging gaps with towels or endlessly wiping puddles off the floor?

A leaking glass shower door isn’t just annoying. It can lead to:

• Slippery floors
• Water damage
• Mold growth

According to the EPA, over 30% of respiratory problems are linked to damp indoor environments.

But here's the good news:

most shower door leaks at the bottom can be fixed easily, affordably, and without replacing your shower.

In this guide, we’ll walk you through:

• Why shower doors leak at the bottom
  
• 2 proven solutions (shower door bottom seals + threshold seals)
  
• When to DIY and when to call a pro

Let’s dive in 👇

 

Why Frameless/Framed/Sliding Shower Doors Leak at Bottom: 5 Common Causes

Before you fix it, you need to know what’s causing it.

If your issue isn’t listed, feel free to tell us in the comments!

Here are the most common reasons:

 

1. A gap at the bottom of the door

Shower doors are designed with a small clearance gap to allow smooth opening and closing. But over time:

• Hinges may loosen

• Doors can start to sag

This creates a larger gap, especially at the bottom corner — and that’s where water escapes.

 

2. Worn or Cracked Seals

Shower seals don’t last forever. They can harden, crack, or come loose with age.

If your door didn’t leak before but now it does, the seal is probably the culprit.

Seals need to be replaced every few years to stay effective.

 

3. Seal Installed Backwards

Yes, it happens. A seal that’s the right product but installed upside-down or facing the wrong way won’t work.

To avoid this common mistake, you can check out our detailed guide on which way should you install a shower seal— it clearly explains the correct orientation for installing your seal.

That’s why all SIMBA seals come with:

• Direction labels

• Clear installation guides

• How-to video tutorials

 

4. Uneven floor or bad slope

If your shower tray or bathroom floor isn’t sloped properly, water may run outwards instead of towards the drain.

Older homes – like Victorian or Edwardian properties – often have slightly uneven floors.

Or the drain might just be a bit slow, especially if it’s partially blocked.

 

 

5. No threshold seal (or seal deliberately left out)

In some installations, especially with frameless or walk-in shower screens, the bottom threshold seal is left out — either for aesthetic reasons or under the assumption that a sloped bathroom curb will prevent leaks.

Some installers even tell homeowners that the floor’s incline will naturally drain water away.

But here’s the truth: when water hits the glass at pressure — especially from handheld or wall-mounted shower heads — it often escapes past the bottom edge, even with a slight slope.

Without a threshold seal, water can easily seep out and spread across the floor, causing puddles and long-term damage.

A minimal, all-glass look might seem appealing, but skipping essential seals often leads to frustration down the line.

Modern shower threshold seals are designed to be discreet — so you don’t have to sacrifice style for a dry bathroom.

 

If none of the above seems to fit, take a photo of the problem and email it to us:
📧 info@showerdoorseal.uk

We’ll help figure out what’s going on – and recommend a proper fix.
We might even add your case to this article to help others too.

And don’t worry – it’s totally free to ask. We're here to help.

 

Common Misconceptions About Sealing the Bottom of Shower Doors

• “Frameless shower doors always leak.” → Not true. With the right shower door bottom seal and threshold, they can be watertight.

• “Caulking everything solves the problem.” → Over-caulking can block drainage channels and make the problem worse.

• “It’s just a few drops, it doesn’t matter.” → Even minor water leaking under shower door track can lead to major damage over time.

Signs Your Shower Door Is Leaking at The Bottom

Look out for these red flags:

• Puddles after every shower

• Water stains on floor or wall

• Peeling paint or bubbling wallpaper

• Warped or rotting skirting boards

• Persistent damp patches

• Musty smell or visible mold

These signs all point to long-term moisture — and possible health risks.

 

 

What Happens If You Ignore It?

• Floor & subfloor damage — Water seeps through cracks and causes wood rot.

• Wall damage — Peeling paint, swollen plasterboard, and structural risk.

• Health issues — Mold spores can lead to asthma and respiratory conditions.

• Hidden costs — Repairing mold and water damage can cost hundreds — even thousands.

 

 

When to Call a Professional

You can usually DIY a leaky shower door fix — but call a pro if:

• The door is badly installed

• The glass or hinges are damaged

• The tray or wall has structural issues

 

How to Seal Bottom of Shower Door: DIY Solutions for All Types

Don’t worry — sealing the bottom of your shower door is easier than you think.

Whether you're dealing with a frameless glass door or a framed one, we will shows you exactly how to seal shower door bottom using two simple, effective components.

 

The Easiest Way to Seal the Bottom of a Shower Door

While re-adjusting the door or tray may help, combining a bottom door seal for shower door with a threshold is usually the simplest fix.

If you're wondering what that plastic piece at the bottom really does, check out our guide: What’s the plastic at the bottom of the shower door? It’s more important than you think.

This combo is the best way to seal the bottom of a glass shower door — stopping leaks before they start.

Related article: Stop Frameless Shower Door Leaks: Fixes for Hinges & Bottom Gaps

Step 1: Fit a Shower Door Seal

Start by installing a PVC shower door seal on your shower door. This simple step helps block water from leaking out at the base.

No need for silicone sealant — just make sure your bottom shower door seal is properly fitted and sized to your glass thickness.

If you're wondering which way the shower screen seal should go, or how to match the right seal to your glass thickness (4mm, 6mm, 8mm, 10mm), check out our guide:
The Ultimate Guide to Buying Shower Door Seals — it includes tips on measuring gaps and choosing the correct fit.

All SIMBA seals come with:

• Marked fitting direction

• Step-by-step video tutorials

• Live support if you get stuck

Remember: Choosing the right bottom seal is the first (and most important) step to a leak-free, stress-free shower.

 

Step 2: Add a Shower Tray Threshold Seal

Now add a clear shower threshold seal to the base of your shower opening.

This creates a small barrier on the shower tray — right below the door.

Double Protection: Why Use Both?

For the best results, use both a shower door seal and a threshold ramp together.

By combining:

• a bottom seal for your shower door
• and a threshold strip on your tray

you create double protection against leaks. This method works especially well for frameless glass showers, where water tends to find every little gap.

 

FAQs

How do I stop water leaking under my shower door?

Install a proper bottom sweep seal and a threshold strip. These components redirect water back into the tray.

 

Why is my framed shower door leaking at the bottom?

Likely due to worn-out seals, poor alignment, or a faulty threshold seals.

 

Do frameless shower doors leak more?

Only if not sealed properly. With the correct bottom seal for frameless shower doors, leaks can be eliminated.

 

What’s the best way to seal the bottom of a glass shower door?

Use a clip-on bottom sweep matched to your glass thickness and add a ramp-style threshold if needed.

 

What’s the best way to replace the seal on the bottom of a shower door?

Follow our full guide on [How To Replace Shower Screen Bottom Seals] — it walks you through every step, from removing the old seal to fitting the new one perfectly.

 

Don’t Let Leaks Win — Choose SIMBA Seal Solutions

At SIMBA, we specialize in shower door bottom seals and accessories for frameless, framed, and sliding doors since 1998.

SIMBA has been helping UK homeowners stop water leaking from the bottom of their shower doors — as one of the go-to suppliers for shower door seals in the UK.

• Factory Direct — Better value than big-name brands
  
• 10-Month Guarantee + Free expert advice before you buy
  
• Free UK Delivery — Arrives in 7–10 days
  
• Clear Install Guides — Step-by-step photos & video
  
• Thicker. Stronger. Better Fit. — Built to last longer than generic versions
  
• Lab-Tested Performance — We don’t just claim our bath seals work — we prove it

For under £20, you can stop the leaks with a proper bottom seal and shower threshold seal — protecting your floor from water damage, mould, and the daily hassle of mopping up.

Compare that with the hundreds you’d spend on repairs later. It’s a no-brainer.

 

Quick Fix Checklist:

• Find the source of the leak

• Install a new bottom shower door seal

• Add a threshold seal for double protection

• Test with water — enjoy a dry bathroom again!

Spend just 1 hour today and say goodbye to soggy mornings for good.

 

Ready to Fix It?

If you're wondering how to seal the bottom of a shower door, this simple two-step method using a seal strip and threshold is your answer. No major tools, no need to re-install your door.

Just clean, clip, and seal.

Ready to stop water leaks for good?

 

This article is intended as general guidance and may not apply to all situations. It is your responsibility to determine the best solution for your own property and circumstances. SIMBA accepts no liability for any damage resulting from the use of advice and/or instructions contained in this blog.

 

 

Partial reference to source:

• U.S. Environmental Protection Agency
• Davidburr
• Thespruce

 

 

 

 

This article was edited by Laura.

Author: Laura  Liu & SIMBA Seal Expert Laura joined SIMBA in January 2017 and has since become an integral part of the team. As a seasoned content manager and seal expert, she oversees website optimization and specializes in crafting informative and engaging content about sealing solutions. Her deep knowledge of shower seal technology and market trends ensures SIMBA stays ahead in providing value to customers worldwide. Facebook ｜ Linkedin

 

 

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