Type Of Shower Door Seals: The Pros and Cons

Introduction

A recent UK home survey revealed that over 45% of homeowners experience some kind of water leakage from their shower doors — mostly caused by worn-out or mismatched shower seal strips, or because they never installed that plastic strip in the first place.

And here’s the kicker: many people don’t even realise there’s more than one type of shower door seal — let alone how to pick the right one.

In this guide, we’ll break down the most common shower door seal types — from sliding door seals to bottom seal strips — and lay out the pros and cons of each. 

Whether you're doing a bit of bathroom DIY or just tired of soggy bath mats, this is the no-fuss, no-fluff guide you need.

Let’s dive in. (Not into a puddle, hopefully.)

1. Types of Bottom Shower Seals

In this article, we’ll look at the different cross-section styles of bottom shower door seals.

To find the right one, you’ll still need to measure your glass thickness — whether it’s 6mm, 8mm, or 10mm.

Check out our guide: How to Measure Your Shower Screen Seal

When it comes to the different types of shower door seals, bottom seals are among the most commonly replaced — and it’s easy to see why.

If your shower is leaking at the bottom, there’s a good chance it’s down to the wrong bottom shower seal, or an old one that’s seen better days.

Single Fin Bottom Seals

At SIMBA, one of the most popular types of shower door seals is the single fin bottom seal.
It has just one fin at the bottom — simple and effective.

For example, our model V456S16 is designed to seal gaps between 13–16mm.

This type of bottom seal is also known as a shower door drip rail seal.

It has a small side rail that helps guide water back down to the floor — keeping it from dripping outside the shower.

That means any bottom shower door seal with a drip rail should always be installed on the inside of the shower enclosure — since its main job is to guide water back into the shower, not out.

For more tips on getting the installation direction right, check out our other guide: “Shower Screen Seal: Which Way Round Should It Go?”

It’ll help you avoid common issues like leaks from installing the seal the wrong way round.

Twin Fin Bottom Shower Seals

Ever noticed that some twin-fin bottom seals have one fin longer than the other?

That’s not a design flaw — it’s actually intentional.

The goal isn’t to boost waterproofing, but to make the shower door glide more smoothly.

If both fins are the same length, they press against the floor at the same time when the door opens or closes.

That pressure can cause the fins to bend, drag, or make the door feel stiff and awkward to use.

With one fin slightly shorter, they touch the floor at different times.

This reduces the friction area and helps the door move more quietly and smoothly.

Now, there’s also a popular type of twin-fin seal in the US market where both fins are equal in length.

We offer this style too on our wholesale site glassseals.com — for example, product J78.

The benefit of equal-length fins is better sealing performance — more contact, more protection.

But here’s the catch: if your gap is too tight, this type of shower door bottom seal can get squeezed, making the door harder to move and noisier when it opens or closes.

Over time, constant rubbing can also wear the seal out faster.

Bulb-Style Bottom Seal

As the name suggests, a bulb-style seal features a soft, rounded "bulb" section designed to press gently against a surface for sealing.

Sounds like a good fit for the bottom of a shower door, right?

Not quite.

Technically, this type of seal is meant to be installed on the side, not the bottom.

But we’ve seen installers using it at the bottom — and it’s really not the right choice.

Why not? It’s all about function and durability.

We explain the full story (with pictures) here:

Why Bulb Shower Door Seals Never Be Installed at the Bottom