What’s That Plastic Bit at the Bottom of My Shower Door?

What’s that plastic strip at the bottom of your shower door—and why does it matter?

If water’s leaking onto your bathroom floor every time you shower, this tiny strip could be the reason.

It’s called a bottom shower door seal, and it’s more important than most people realise.

But what if it’s looking grimy, cracked, or even falling off?

Can you replace it yourself? Can you remove and clean it—or will it be impossible to reinstall?

Good news: you’re not the only one wondering, and this quick guide will walk you through everything.

We’ll show you:

• What this strip actually does (and why it matters)
• How to choose the right replacement
• How to fix common leaks for good—even without a plumber

Let’s break it down step by step.

1. What is the plastic at the bottom of a shower door?

The plastic bit you see at the bottom of your shower screen is called a shower door bottom gasket – or sometimes a shower door bottom seal.

Here in the UK, people often refer to it as a shower bottom screen seal.

Usually made from clear or frosted plastic, it clips onto the bottom or side edge of your glass shower door.

Its job? To stop water leaking onto your bathroom floor.

There are a few Different type of shower door sweep.

There are different types—some have drip rails, others are F- or H-shaped, or come with double fins.

Attention needs to be paid to the direction of installation of these bottom seals.

But they all do the same thing:

Keep water inside the shower and out of your hallway.

2. Why does the plastic at the bottom matter?

Some fitters skip the bottom door seal for shower door—just to keep the shower door looking sleek.

They’ll say things like:

“Don’t worry, the tray’s sloped. Water won’t leak.”

But that’s not enough.

Sure, a sloped tray helps.

But you still need a proper shower door bottom seal.

When that bottom sweep is missing or worn out, small issues can turn into big ones:

• Water leaks onto the floor
• Slippery tiles = higher risk of falls
• Mould and limescale build-up
• More scrubbing and cleaning
• Long-term moisture damage to floors and walls

That little plastic strip does more than you think.

It keeps your bathroom clean, dry, and safe.

3. When should you replace your bottom door seal for shower door?

Replacing the bottom seal isn’t just “nice to have” — it’s essential if you want a leak-free shower and a dry bathroom floor.

The plastic strip at the bottom of your shower screen won’t last forever.

Over time, it wears out, hardens, or even warps — and when that happens, it simply stops doing its job.

Wondering if it’s time to swap yours? Look out for these signs:

• It’s turned yellow, brittle, or has visible cracks

• It keeps falling off or feels loose when you open the door

• You notice puddles or water trails after every shower

• There’s a visible gap between the glass door and the tray

If any of these sound familiar, it’s time for a new bottom seal.

The good news? You can absolutely do it yourself — and no, you don’t need a toolbox or a tradesperson.

Just follow our easy guide to resealing a shower door properly, where we walk you through the entire process — from removing the old strip to fitting the new one snugly and securely.

4. How do you choose the right shower door bottom trim?

It all comes down to size and shape. Here's how to get it right:

✅ Measure the thickness of your glass (usually 6mm, 8mm, 10mm, or 12mm)
✅ Check the height of the gap between the door and the tray
✅ Look at the shape of your current seal (a side photo really helps)

Still unsure? No worries — our team is here to help.

Need more detail? Head over to our full  Shower Door Seal Buying Guide.

5. Not sure which seal to pick? SIMBA can help — for free!

James Liu, founder of SIMBA, has over 30 years of experience with shower bottom seal strips. From awkward gaps to odd door shapes, he’s seen it all.

To help you choose the best seal, check out our comprehensive guide on How to Judge the Quality of Shower Door Seal Strips and avoid common installation problems.

If you’re stuck, just send us:

• A photo of your shower door
• A side photo of the seal (if you have it)
• The size of the gap you've measured

James will take a look and give you honest advice — no pressure, no sales talk.

📧 Email: info@showerdoorseal.uk
(We might even share your case on our site — anonymously — to help others.)

6. Ready to get a new one?

At SIMBA, we make our own bottom of glass shower door seals — direct from the factory, no middlemen.

That means better quality, longer life, and easier fitting.

[Click here to browse our full shower door seal collection]
(Built to last. Easy to fit. Designed to keep water where it belongs.)

Final thoughts

That plastic strip at the bottom of your shower door might seem small — but it does a big job.

If yours is cracked, yellow, loose, or missing, it’s time for a new one.

Still unsure? Just send us a quick photo — we’ll help you find the right seal at bottom of shower door, no charge.

This article was edited by Laura.