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

 

Last updated: 2025-11-19

 

Is your glass shower door leaking at the bottom every time you use it? Tired of stuffing towels into the gaps?

Water under the shower door is one of the most common. 

It leads to: slippery floors, water damage, and mould growth. The EPA even links respiratory problems to damp indoor spaces.

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

But don't stress. Most shower door bottom leaks are incredibly easy to sort out.

You won't need a pro or a new shower—sometimes, all you need is a simple transparent shower door bottom gasket!

In this guide, we'll show you:

• Why leaks happen at the bottom.
• The simple two-step solution to fix it.
• How to seal tricky spots like sliding doors and corners.

Let’s dive in 👇

 

Why Your Shower Door Leaks at the Bottom

Before you fix it, you need to know what’s causing it. Here are the 5 most common reasons your frameless, sliding door, or screen is letting water escape:

 

A Gap at the Base

All shower doors have a clearance gap. However, loosened hinges or a sagging door can make this gap too large, letting water escape, especially at the bottom corner.

 

 

Worn or Cracked Seals

Seals harden, crack, or come loose with age. If your door didn’t leak before but does now, the shower door bottom seal is the likely culprit. Seals need replacing every few years.

 

 

Seal Installed Backwards

Yes, it happens! A seal facing the wrong way actively pushes water out. To avoid this, all SIMBA seals come with clear direction labels, installation guides, and how-to video tutorials.

 

Uneven Floor/Bad Slope

In older homes (like Victorian or Edwardian properties), floors can be slightly uneven. If the shower tray or floor isn't sloped right, water runs outwards.

 

 

No Threshold Seal

Installers sometimes skip the minimal threshold seal for aesthetics. But when water hits the glass at pressure, it easily escapes past the edge. You don't have to sacrifice style; modern thresholds are designed to be discreet.

 

 

 

The 2-Step Solution: How To Seal the Bottom

Whether it’s a frameless shower door, a sliding door, or just a fixed screen, the solution for bottom leaks is the same. Don't stress—it's easier than you think.

We recommend combining two simple, effective steps for maximum protection:

 

 

Step 1: Install a Shower Door Seal

Start by installing the correct PVC shower door seal directly onto the bottom of your glass.

• This step blocks the water immediately at the base.

• No silicone needed. Just ensure the seal is the correct size for your glass thickness and gap.

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

 

 

 

Step 2: Add a Shower Tray Threshold Seal

Next, add a clear shower threshold seal to the base of your shower opening (right below the door).

• This creates a small physical barrier or ramp on the shower tray.

• Double Protection: Combining the bottom seal on the door and the threshold strip on the tray creates double protection. This method works especially well for frameless glass showers, where water loves to find every tiny gap.

 

 

Solving Tricky Leaks

Leaking at Hinges, Corners, or Sliding Doors?

If you've fixed the bottom but still have leaks elsewhere, the problem is more specific.

• Corner Leaks: If your shower is leaking at the corner, you need to focus on where the vertical seals meet.

• Hinge Leaks: These often require specific, sometimes trimmed, vertical seals.

• Sliding Door Bottom Leaks: If there’s no plastic strip running along the bottom edge, that is your problem. We recommend a seal like the S6DTL which is specifically designed for sliding doors.

We’ve already covered these complex fixes in depth.

For a full breakdown of how to stop leaks at hinges, corners, and on folding screens, please read our ultimate guide here: Stop Hinges & Bottom & Corner Frameless Shower Door Leaks Solution Quickly

 

 

 

 

Conclusion & SIMBA Support

Don’t let water ruin your floor. For under £20, you can stop the leaks with a proper bottom seal and shower threshold seal, protecting your home from water damage and mould.

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

 

Still Unsure? Just Send Us a Photo.

We’ve helped thousands of households fix bathroom leaks. Snap a photo of your problem area and email it to us at: 📧 info@showerdoorseal.uk

Our customer service team will get in touch and help you sort it out—it's quick, free, and professional.

 

 

FAQs

How do I stop water leaking under my shower door?

Install a proper bottom sweep seal and a ramp-style threshold strip.

 

Do frameless shower doors leak more?

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

 

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.

 

 

Why Choose SIMBA?

• Factory Direct: Better value than big-name brands.

• 10-Month Guarantee + Free expert advice before you buy.

• Thicker. Stronger. Better Fit. Built to last longer than generic versions.

 

 

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.